{"id":22416,"date":"2026-08-28T07:51:48","date_gmt":"2026-08-28T05:51:48","guid":{"rendered":"https:\/\/www.curiaweb.ch\/?post_type=docs&#038;p=22416"},"modified":"2026-08-28T07:51:49","modified_gmt":"2026-08-28T05:51:49","password":"","slug":"wordpress-critical-error-white-screen","status":"publish","type":"docs","link":"https:\/\/www.curiaweb.ch\/en\/hilfe\/wordpress\/wordpress-kritischer-fehler-weisse-seite\/","title":{"rendered":"WordPress shows a white screen or a critical error: What to do?"},"content":{"rendered":"<p class=\"wp-block-paragraph\">Instead of your WordPress website, suddenly only a white page appears or the message that a critical error has occurred on the website. Often, a fatal PHP error has occurred, which prevents WordPress from fully executing the requested page.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For example, the cause can be a faulty or incompatible plugin, a theme, custom PHP code, an unsuitable PHP version, or an exhausted memory limit.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The important thing now is not to delete files at random or change multiple settings at once. With systematic troubleshooting, the cause can usually be narrowed down much faster.<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><strong>Briefly explained:<\/strong> First, check what was changed immediately before the error occurred and whether WordPress sent a recovery email to the administrator address. After that, you should specifically investigate plugins, the theme, the PHP version, the memory limit, and error logs. Whenever possible, change only one thing at a time.<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\">There has been a critical error on your website<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">WordPress can detect fatal PHP errors that prevent a request from executing normally.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Instead of displaying technical PHP error messages to visitors, a productive WordPress website often simply shows a generic message about a critical error.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">As a result, the actual technical cause is not immediately visible in the browser.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Typical causes are:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>faulty or incompatible plugin<\/li>\n\n\n\n<li>Plugin conflict<\/li>\n\n\n\n<li>faulty or incompatible theme<\/li>\n\n\n\n<li>Error in self-inserted PHP code<\/li>\n\n\n\n<li>incompatible PHP version<\/li>\n\n\n\n<li>reached PHP memory limit<\/li>\n\n\n\n<li>corrupted files after an update<\/li>\n\n\n\n<li>Issues with WordPress core files<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">What is the \u201eWhite Screen of Death\u201c?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">As <strong>White Screen of Death<\/strong>, often with <strong>WSOD<\/strong> abbreviated, it refers to a completely or largely empty white page where WordPress does not output a helpful error message.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Such a white page can also be caused by PHP or database errors.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Modern WordPress versions feature a fatal error handler and a recovery mode. That is why today, in the event of certain errors, the message about a critical error appears more frequently instead of the classic completely white screen.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">However, the underlying problem remains similar: WordPress could not complete the request normally due to a fatal error.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">1. Think first: What was changed immediately before?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The most important initial diagnostic step is often not technical.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Consider what happened immediately before the error occurred.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For example:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>WordPress has been updated<\/li>\n\n\n\n<li>a plugin was updated<\/li>\n\n\n\n<li>several plugins were updated simultaneously<\/li>\n\n\n\n<li>a new plugin has been installed<\/li>\n\n\n\n<li>a plugin has been activated<\/li>\n\n\n\n<li>The theme has been updated<\/li>\n\n\n\n<li>a new theme has been activated<\/li>\n\n\n\n<li>the PHP version has been changed<\/li>\n\n\n\n<li>Code was in <code>functions.php<\/code> inserted<\/li>\n\n\n\n<li><code>wp-config.php<\/code> has been edited<\/li>\n\n\n\n<li>a code snippet has been activated<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">If the error occurred immediately after a specific change, that change is the first logical starting point for diagnosis.<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><strong>Practical Tip:<\/strong> Note down what you change during troubleshooting. If you change the PHP version, theme, and five plugins all at once and the website works again afterwards, you won't know what the actual cause was.<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\">2. Check if only one page or the entire website is affected<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A critical error does not necessarily have to affect the complete WordPress installation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Therefore, test different areas of the website:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Home<\/li>\n\n\n\n<li>a normal subpage<\/li>\n\n\n\n<li>a blog post<\/li>\n\n\n\n<li>WordPress Login<\/li>\n\n\n\n<li>WordPress admin area<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The admin area is usually accessible via an address following this pattern:<\/p>\n\n\n\n<figure class=\"wp-block-embed\"><div class=\"wp-block-embed__wrapper\">\nhttps:\/\/deine-domain.ch\/wp-admin\n<\/div><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">For example, if only a single page fails, the cause may lie in a specific block, shortcode, template, or plugin that is used only on that page.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If neither the frontend nor the admin area works against this, there is likely a more fundamental problem.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Check WordPress administrator email<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">In the event of certain fatal errors, WordPress automatically activates its recovery mode and attempts to send a message to the administrator email address stored in WordPress.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Therefore, check:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Inbox of the administrator address<\/li>\n\n\n\n<li>spam or junk folder<\/li>\n\n\n\n<li>if applicable, further email account filters<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The message may contain information about which plugin or theme triggered the error, as well as a special link for the WordPress recovery mode.<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><strong>Important:<\/strong> If no recovery email arrives, it does not mean that there is no critical WordPress error. For example, the message may not be delivered due to a mail issue, or the specific error may occur outside the conditions under which WordPress activates Recovery Mode.<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\">4. Use WordPress Recovery Mode<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">If you received a corresponding email from WordPress, you can use the recovery link contained within it.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">After logging in, WordPress indicates that recovery mode is active.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A faulty plugin or theme can be paused for your recovery session so that you can regain access to the admin area and investigate the cause.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">WordPress can display notices there indicating which component caused an error.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Depending on the cause, you can, for example:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>disable a problematic plugin<\/li>\n\n\n\n<li>change a faulty theme<\/li>\n\n\n\n<li>investigate a problematic update<\/li>\n\n\n\n<li>correct flawed own code<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Do not exit Recovery Mode until you have addressed the suspected cause and checked the website.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">5. Does the WordPress admin area still work?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">If you can still open the admin area normally, troubleshooting is much easier.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Open:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Plugins \u2192 Installed Plugins<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If the error started after installing, activating, or updating a plugin, first deactivate that plugin.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Check the affected page again afterwards.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If the error disappears, you have a strong indication of the cause. However, this does not necessarily mean that the plugin is fundamentally faulty. For example, a conflict with another plugin, the theme, the WordPress version, or the PHP version used is also possible.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">We cover a detailed diagnosis in the article <a href=\"\/en\/help\/wordpress\/wordpress-plugin-theme-conflicts\/\">Identifying and Resolving Plugin or Theme Conflicts in WordPress<\/a>.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">6. Admin area not accessible: Manually deactivate plugin<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">If a plugin causes a fatal error and you can no longer access the WordPress admin area, the affected plugin can possibly be deactivated via file access.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">WordPress plugins are usually located under:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><code>wp-content\/plugins\/<\/code><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If the error log, for example, clearly points to a plugin with the directory<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><code>wp-content\/plugins\/beispiel-plugin\/<\/code><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">refers, its folder can be temporarily renamed.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For example:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><code>example-plugin-deactivated<\/code><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">WordPress will then no longer find the plugin under its previous path and cannot load it normally.<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><strong>Attention:<\/strong> Do not randomly rename all plugin directories. If you already have a specific suspicion or a clear entry in the error log, start with that exact component.<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\">7. What to do if no specific plugin is known?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">If there is no error log and you do not know which plugin is causing the error, a controlled deactivation of the plugins may be necessary as a diagnostic measure.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If the admin area is accessible, you should do this there.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If he is unreachable, the plugin directory can also be temporarily renamed via file access, provided you have the appropriate experience.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The folder is usually:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><code>wp-content\/plugins\/<\/code><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If the entire folder is temporarily renamed, WordPress can no longer load the regular plugins located inside it under the expected path.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If the website works again afterwards, this strongly indicates that one of the plugins is involved.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">After that, the plugins must be reactivated in a controlled manner or investigated in order to find the actual culprit.<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><strong>Important:<\/strong> \u201eWebsite works without plugins does not yet identify the faulty plugin. The actual diagnosis only begins then: reactivate plugins individually or in sensible groups and test after each change.<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\">8. Check themes as a cause of error<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Not only plugins can cause a critical error. A theme can also contain faulty PHP code or code that is incompatible with the current environment.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A theme is particularly suspicious if the error occurred immediately after:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>a theme update<\/li>\n\n\n\n<li>a theme change<\/li>\n\n\n\n<li>to a change in <code>functions.php<\/code><\/li>\n\n\n\n<li>an adaptation of a child theme<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">occurred.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If the admin area is accessible, you can activate a current WordPress default theme for testing purposes.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If the website works again with this, the previous theme should be examined more closely.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">9. Check theme if admin area is inaccessible<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Themes are usually located at:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><code>wp-content\/themes\/<\/code><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">During a manual diagnosis, the active theme's directory can be temporarily renamed.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For WordPress to then be able to fall back on a different theme, a suitable alternative theme must be installed.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Such a change can significantly alter the appearance of the website and should therefore be used specifically for diagnosis.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">10. Error after changing the PHP version<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">If the critical error occurred immediately after a change of the PHP version, the compatibility of the WordPress installation should be checked.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">WordPress itself, plugins, and themes must be compatible with the PHP version being used.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Especially older plugins, themes, or custom code may use functions that have been modified or removed in a newer PHP version.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Conversely, modern software may require features that are not yet available in a very old PHP version.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">We cover the systematic approach in detail in <a href=\"\/en\/help\/wordpress\/change-wordpress-php-version\/\">Change PHP version for WordPress and check compatibility<\/a>.<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><strong>Practical Tip:<\/strong> If a website fails immediately after a PHP version change, document the previous and the new PHP version. This information is much more helpful for troubleshooting than the general statement \u201eWordPress is no longer working\u201c.<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\">11. PHP Memory Limit as a potential cause<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">WordPress, plugins, and themes require memory during execution. If a PHP process exceeds the allowed memory limit, processing can abort with a fatal error.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For example, a message containing the following element may then appear in the error log:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><code>Allowed memory size ... exhausted<\/code><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In this case, the storage limit should not automatically just be increased.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">An unusually high memory consumption can be caused by, for example:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>a resource-intensive plugin<\/li>\n\n\n\n<li>a programming error<\/li>\n\n\n\n<li>a very complex operation<\/li>\n\n\n\n<li>an unfavorable plugin combination<\/li>\n\n\n\n<li>an import or export operation<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">be caused.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The differences between PHP <code>memory_limit<\/code>, WordPress memory limits, and an actual cause of the error are explained in the article <a href=\"\/en\/help\/wordpress\/wordpress-php-memory-limit\/\">PHP Memory Limit in WordPress: Identify and fix errors<\/a>.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">12. Use error logs instead of assumptions<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">When the obvious cause is not apparent, error logs are often the most important next step.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A log can show, for example:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>which PHP file triggered the error<\/li>\n\n\n\n<li>which plugin is affected<\/li>\n\n\n\n<li>whether the error comes from the theme<\/li>\n\n\n\n<li>which PHP function is involved<\/li>\n\n\n\n<li>whether the storage limit has been reached<\/li>\n\n\n\n<li>in which file and on which line the error occurred<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">A typical entry might contain a path like this, for example:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><code>\/wp-content\/plugins\/sample-plugin\/...<\/code><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is much more meaningful than just the visible critical error message.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">13. Enable WordPress debugging selectively<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">WordPress has its own debugging functions. These can be used to log PHP errors, warnings, and notices.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Among the most important constants are:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>WP_DEBUG<\/code><\/li>\n\n\n\n<li><code>WP_DEBUG_LOG<\/code><\/li>\n\n\n\n<li><code>WP_DEBUG_DISPLAY<\/code><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">For a production website, detailed error messages should generally not be displayed publicly in the frontend. They can contain internal paths, technical details, or other information that visitors should not see.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">How to use debugging safely and <code>debug.log<\/code> you evaluate, we will discuss in detail in <a href=\"\/en\/help\/wordpress\/wordpress-debugging-fehlerprotokolle\/\">Enable WordPress debugging and use error logs<\/a>.<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><strong>Attention:<\/strong> Do not simply enable the permanent public output of all PHP errors on a production website. For troubleshooting, controlled logging is usually more sensible than making technical error messages visible to every visitor.<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\">14. Where is the WordPress debug log located?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">When WordPress debugging has been configured accordingly, the default debug log is normally created at the following path:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><code>wp-content\/debug.log<\/code><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Whether the file exists and which entries it contains depends on the debug configuration and the errors that actually occur.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A log should not remain unnecessarily publicly accessible after troubleshooting is completed.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">15. How to correctly read a Fatal Error<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A PHP error message can seem complicated at first glance. For the initial diagnosis, however, a few components are often particularly interesting:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Type of error<\/li>\n\n\n\n<li>File path<\/li>\n\n\n\n<li>Filename<\/li>\n\n\n\n<li>Line number<\/li>\n\n\n\n<li>affected function or class<\/li>\n\n\n\n<li>Time of the error<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">For example, if the path says:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><code>wp-content\/plugins\/...<\/code><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">a plugin is involved.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Does it say:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><code>wp-content\/themes\/...<\/code><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">leads in the direction of the theme or child theme.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">However, a file path alone does not always prove that this exact component is the actual cause. For example, an error may have been triggered by a call from another component.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">16. Syntax error after manual code modification<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">If you manually edited PHP code immediately before the failure, this change should be checked first.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A small syntax error can be enough to trigger a fatal PHP error.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Changes to files such as the following are particularly critical:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><code>functions.php<\/code><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">or:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><code>wp-config.php<\/code><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If you still know exactly which change caused the error, restore the previous working code.<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><strong>Important:<\/strong> Do not blindly copy PHP code from forums, videos, or AI outputs into a production WordPress website. Check what the code is intended for, whether it fits your current environment, and whether you have a way to restore it.<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\">17. Errors immediately after a WordPress update<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A critical error after a WordPress update does not automatically mean that WordPress itself is faulty.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For example, an update can reveal that:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>an older plugin is no longer compatible<\/li>\n\n\n\n<li>a theme uses deprecated code<\/li>\n\n\n\n<li>own code is no longer compatible<\/li>\n\n\n\n<li>an update was not fully completed<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Therefore, first check the specific error message or error log.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">An immediate downgrade without diagnosis can merely mask the problem and additionally cause security or compatibility issues.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">18. Error immediately after a plugin update<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">If the website crashes immediately after updating a specific plugin, that plugin is an obvious starting point.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Check:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>whether the plugin is mentioned in the error log<\/li>\n\n\n\n<li>whether another update is available<\/li>\n\n\n\n<li>whether the developer documents known issues<\/li>\n\n\n\n<li>whether the used WordPress and PHP version is supported<\/li>\n\n\n\n<li>whether there is a conflict with another extension<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Temporarily deactivate the plugin if necessary to make the website accessible again and further isolate the cause.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">19. Error after activating a new plugin<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">If a critical error appears immediately after activating a new plugin, the diagnosis is comparatively straightforward to begin.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Deactivate the newly activated plugin again.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If the website works normally afterwards, it should be checked before reactivation why the plugin is causing the error.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Possible reasons are:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Incompatibility with PHP<\/li>\n\n\n\n<li>Incompatibility with WordPress<\/li>\n\n\n\n<li>Conflict with another plugin<\/li>\n\n\n\n<li>Theme conflict<\/li>\n\n\n\n<li>missing PHP extension<\/li>\n\n\n\n<li>Programming error in the plugin<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">20. Nicht sofort ein Backup zur\u00fcckspielen<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Ein Backup ist f\u00fcr die Wiederherstellung einer Website sehr wichtig. Es sollte aber nicht automatisch der allererste Schritt bei jedem kritischen Fehler sein.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Wenn beispielsweise nur ein neu aktiviertes Plugin den Fehler verursacht, kann dessen Deaktivierung wesentlich schneller und sauberer sein als die vollst\u00e4ndige Wiederherstellung einer \u00e4lteren Website-Version.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Ein Backup-Restore kann au\u00dferdem neuere Inhalte, Bestellungen, Formulareingaben oder andere seit dem Sicherungszeitpunkt entstandene Daten \u00fcberschreiben.<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><strong>Recommendation:<\/strong> Ermittle nach M\u00f6glichkeit zuerst die Ursache. Eine vollst\u00e4ndige Wiederherstellung ist besonders dann sinnvoll, wenn Dateien oder Daten besch\u00e4digt wurden oder eine kontrollierte R\u00fcckkehr zu einem bekannten funktionierenden Zustand erforderlich ist.<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\">21. Wann ein Backup trotzdem die richtige L\u00f6sung ist<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Eine Wiederherstellung kann sinnvoll sein, wenn beispielsweise:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>zahlreiche Dateien besch\u00e4digt wurden<\/li>\n\n\n\n<li>eine fehlgeschlagene \u00c4nderung nicht sauber r\u00fcckg\u00e4ngig gemacht werden kann<\/li>\n\n\n\n<li>mehrere Komponenten gleichzeitig ver\u00e4ndert wurden<\/li>\n\n\n\n<li>Schadcode oder Manipulation vermutet wird<\/li>\n\n\n\n<li>ein bekannter funktionierender Sicherungsstand ben\u00f6tigt wird<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Bei dynamischen Websites wie WooCommerce-Shops muss besonders sorgf\u00e4ltig gepr\u00fcft werden, welche Daten durch einen Restore \u00fcberschrieben w\u00fcrden.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">22. Cache nach der Fehlerbehebung ber\u00fccksichtigen<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Wenn die eigentliche Ursache behoben wurde, kann eine zwischengespeicherte Fehlerseite unter Umst\u00e4nden noch sichtbar sein.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Je nach Website k\u00f6nnen verschiedene Cache-Ebenen beteiligt sein:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>browser cache<\/li>\n\n\n\n<li>WordPress cache plugin<\/li>\n\n\n\n<li>Server- beziehungsweise Page-Cache<\/li>\n\n\n\n<li>CDN oder Proxy<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Leere Cache-Systeme jedoch nicht reflexartig als ersten Diagnoseschritt. Ein PHP-Fatal-Error wird durch das L\u00f6schen des Browser-Caches nicht repariert.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">23. Ist eine weisse Seite immer ein WordPress-Fehler?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">No.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Eine scheinbar leere Seite kann auch andere Ursachen haben, beispielsweise:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>CSS blendet Inhalte aus<\/li>\n\n\n\n<li>JavaScript verhindert die erwartete Darstellung<\/li>\n\n\n\n<li>eine leere Template-Ausgabe<\/li>\n\n\n\n<li>ein Cache liefert fehlerhaften Inhalt<\/li>\n\n\n\n<li>eine externe Abh\u00e4ngigkeit verursacht Probleme<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Deshalb ist es wichtig, zwischen einer tats\u00e4chlich leeren Serverantwort, einem PHP-Fatal-Error und einer lediglich optisch leeren Seite zu unterscheiden.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">24. Kritischer Fehler oder HTTP 500?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Ein schwerwiegender PHP-Fehler kann sich je nach Server- und WordPress-Konfiguration auch als HTTP-500-Fehler bemerkbar machen.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A <strong>500 Internal Server Error<\/strong> ist allerdings allgemeiner und kann neben PHP-Fehlern weitere Ursachen haben.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Wenn dein Browser ausdr\u00fccklich einen Fehler 500 meldet, findest du die gezielte Diagnose im Artikel <a href=\"\/en\/help\/wordpress\/how-to-fix-wordpress-error-500\/\">How to fix WordPress error 500<\/a>.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">25. Kritischer Fehler oder Website komplett nicht erreichbar?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Wenn \u00fcberhaupt keine Verbindung zur Website aufgebaut werden kann, muss WordPress nicht zwingend die Ursache sein.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Auch folgende Bereiche k\u00f6nnen eine Rolle spielen:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Domain<\/li>\n\n\n\n<li>DNS<\/li>\n\n\n\n<li>Webserver<\/li>\n\n\n\n<li>SSL<\/li>\n\n\n\n<li>Hosting<\/li>\n\n\n\n<li>Netzwerk<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">F\u00fcr diesen Fall verwenden wir eine breitere Diagnose im Artikel <a href=\"\/en\/help\/wordpress\/wordpress-website-nicht-erreichbar\/\">WordPress website not accessible: systematically check causes<\/a>.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">26. Website funktioniert wieder \u2013 ist das Problem damit erledigt?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Not necessarily.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Wenn du beispielsweise ein Plugin deaktiviert hast und die Website wieder funktioniert, hast du zun\u00e4chst das Symptom beseitigt.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Danach solltest du noch kl\u00e4ren:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>warum das Plugin den Fehler verursacht hat<\/li>\n\n\n\n<li>ob eine kompatible Version verf\u00fcgbar ist<\/li>\n\n\n\n<li>ob das Plugin weiterhin ben\u00f6tigt wird<\/li>\n\n\n\n<li>ob ein Konflikt mit einer anderen Komponente besteht<\/li>\n\n\n\n<li>ob weitere Fehler im Log vorhanden sind<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Ein kritischer Fehler sollte nicht dadurch \u201egel\u00f6st\u201c werden, dass die Ursache vergessen wird, sobald die Startseite wieder erscheint.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">27. Debugging nach der Fehlersuche wieder deaktivieren<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Wenn du f\u00fcr die Diagnose WordPress-Debugging aktiviert hast, solltest du die Einstellungen nach Abschluss der Fehlersuche wieder auf einen f\u00fcr die produktive Website geeigneten Zustand zur\u00fccksetzen.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Insbesondere detaillierte Fehlermeldungen sollten nicht dauerhaft \u00f6ffentlich ausgegeben werden.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Auch erzeugte Logdateien sollten hinsichtlich Inhalt, Speicherplatz und Zugriff kontrolliert werden.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">28. Reihenfolge f\u00fcr eine systematische Fehlersuche<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Wenn WordPress einen kritischen Fehler oder eine weisse Seite zeigt, kannst du dich grunds\u00e4tzlich an folgender Reihenfolge orientieren:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Ruhe bewahren und keine wahllosen \u00c4nderungen durchf\u00fchren.<\/li>\n\n\n\n<li>Pr\u00fcfen, was unmittelbar vor dem Fehler ge\u00e4ndert wurde.<\/li>\n\n\n\n<li>Kontrollieren, welche Bereiche der Website betroffen sind.<\/li>\n\n\n\n<li>Administrator-E-Mail und Spam-Ordner pr\u00fcfen.<\/li>\n\n\n\n<li>Recovery Mode verwenden, falls verf\u00fcgbar.<\/li>\n\n\n\n<li>Zuletzt ge\u00e4ndertes Plugin oder Theme untersuchen.<\/li>\n\n\n\n<li>PHP-Version pr\u00fcfen, insbesondere nach einer \u00c4nderung.<\/li>\n\n\n\n<li>Fehlerprotokolle auswerten.<\/li>\n\n\n\n<li>Bei Bedarf WordPress-Debugging kontrolliert aktivieren.<\/li>\n\n\n\n<li>Memory-Limit pr\u00fcfen, wenn das Log darauf hinweist.<\/li>\n\n\n\n<li>Fix the root cause specifically.<\/li>\n\n\n\n<li>Frontend und Adminbereich vollst\u00e4ndig testen.<\/li>\n\n\n\n<li>Debugging-Einstellungen wieder kontrollieren.<\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading\">29. Was du bei einem kritischen Fehler besser nicht tun solltest<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>nicht wahllos WordPress-Dateien l\u00f6schen<\/li>\n\n\n\n<li>nicht mehrere Plugins gleichzeitig l\u00f6schen, ohne die Ursache zu dokumentieren<\/li>\n\n\n\n<li>nicht sofort die Datenbank ver\u00e4ndern<\/li>\n\n\n\n<li>nicht beliebige PHP-Werte erh\u00f6hen, ohne die Fehlermeldung zu verstehen<\/li>\n\n\n\n<li>nicht ungepr\u00fcft auf eine alte PHP-Version wechseln<\/li>\n\n\n\n<li>nicht s\u00e4mtliche Dateiberechtigungen ver\u00e4ndern<\/li>\n\n\n\n<li>nicht sofort ein altes Backup \u00fcber eine aktuelle dynamische Website spielen<\/li>\n\n\n\n<li>nicht detaillierte PHP-Fehler dauerhaft \u00f6ffentlich anzeigen<\/li>\n\n\n\n<li>nicht die alte funktionierende Konfiguration vergessen, bevor du \u00c4nderungen vornimmst<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">30. Welche Informationen helfen dem Support?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Je genauer die Ausgangslage beschrieben wird, desto schneller kann ein technischer Fehler normalerweise eingegrenzt werden.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For example, the following are helpful:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>affected domain<\/li>\n\n\n\n<li>genaue sichtbare Fehlermeldung<\/li>\n\n\n\n<li>Zeitpunkt, seit dem der Fehler auftritt<\/li>\n\n\n\n<li>letzte \u00c4nderung vor Auftreten des Fehlers<\/li>\n\n\n\n<li>zuletzt aktualisiertes Plugin oder Theme<\/li>\n\n\n\n<li>verwendete PHP-Version<\/li>\n\n\n\n<li>whether the frontend and admin area are affected<\/li>\n\n\n\n<li>relevanter Eintrag aus dem Error Log<\/li>\n\n\n\n<li>ob eine WordPress-Recovery-E-Mail angekommen ist<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Wenn ein Fehlerprotokoll vorhanden ist, sollte der relevante Abschnitt mit Zeitstempel \u00fcbermittelt werden. Ein vollst\u00e4ndiges Log mit Tausenden alten Meldungen ist f\u00fcr eine gezielte Diagnose h\u00e4ufig weniger hilfreich.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">When should you contact CURIAWEB support?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Wenn deine WordPress-Website bei CURIAWEB einen kritischen Fehler oder eine weisse Seite zeigt und du die Ursache nicht eindeutig identifizieren kannst, kann der Support bei der technischen Eingrenzung der Hosting- und WordPress-Umgebung helfen.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Kontaktiere den Support insbesondere, wenn:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Frontend und Adminbereich nicht mehr erreichbar sind<\/li>\n\n\n\n<li>du die Fehlermeldung im Log nicht einordnen kannst<\/li>\n\n\n\n<li>der Fehler nach einer \u00c4nderung der PHP-Version auftrat<\/li>\n\n\n\n<li>ein Speicher- oder PHP-Fehler angezeigt wird<\/li>\n\n\n\n<li>du unsicher bist, bevor du Dateien oder Einstellungen manuell ver\u00e4nderst<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Sende keine Passw\u00f6rter unaufgefordert mit. Beschreibe stattdessen m\u00f6glichst genau, wann der Fehler begonnen hat und welche \u00c4nderung unmittelbar davor durchgef\u00fchrt wurde.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Summary<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Eine weisse WordPress-Seite oder die Meldung \u00fcber einen kritischen Fehler weist h\u00e4ufig auf einen schwerwiegenden PHP-Fehler hin. Typische Ursachen sind Plugins, Themes, eigener Code, PHP-Inkompatibilit\u00e4ten oder ein ausgesch\u00f6pftes Speicherlimit.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Pr\u00fcfe zuerst, was unmittelbar vor dem Fehler ge\u00e4ndert wurde. Kontrolliere danach die Administrator-E-Mail auf eine Nachricht zum WordPress Recovery Mode und untersuche verd\u00e4chtige Plugins oder Themes.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Wenn die Ursache nicht offensichtlich ist, solltest du Fehlerprotokolle verwenden, statt Einstellungen auf Verdacht zu ver\u00e4ndern. Dateipfade und Fehlertypen liefern h\u00e4ufig konkrete Hinweise darauf, welche Komponente beteiligt ist.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Eine systematische Diagnose ist dabei wichtiger als eine m\u00f6glichst schnelle Folge von \u00c4nderungen: Ursache identifizieren, gezielt beheben, Website testen und tempor\u00e4r aktivierte Debugging-Massnahmen anschlie\u00dfend wieder zur\u00fccksetzen.<\/p>","protected":false},"excerpt":{"rendered":"<p>Statt deiner WordPress-Website erscheint pl\u00f6tzlich nur noch eine weisse Seite oder die Meldung, dass auf der Website ein kritischer Fehler aufgetreten ist. H\u00e4ufig ist dann ein schwerwiegender PHP-Fehler aufgetreten, durch den WordPress die angeforderte Seite nicht mehr vollst\u00e4ndig ausf\u00fchren kann. Die Ursache kann beispielsweise ein fehlerhaftes oder inkompatibles Plugin, ein Theme, eigener PHP-Code, eine ungeeignete [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_joinchat":[],"footnotes":""},"doc_category":[80],"doc_tag":[],"class_list":["post-22416","docs","type-docs","status-publish","hentry","doc_category-wordpress"],"year_month":"2026-09","word_count":3257,"total_views":"5","reactions":{"happy":"0","normal":"0","sad":"0"},"author_info":{"name":"Silvio Mazenauer","author_nicename":"admin-curia","author_url":"https:\/\/www.curiaweb.ch\/en\/author\/admin-curia\/"},"doc_category_info":[{"term_name":"WordPress","term_url":"https:\/\/www.curiaweb.ch\/en\/hilfe-kategorie\/wordpress\/"}],"doc_tag_info":[],"knowledge_base_info":[],"knowledge_base_slug":[],"_links":{"self":[{"href":"https:\/\/www.curiaweb.ch\/en\/wp-json\/wp\/v2\/docs\/22416","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.curiaweb.ch\/en\/wp-json\/wp\/v2\/docs"}],"about":[{"href":"https:\/\/www.curiaweb.ch\/en\/wp-json\/wp\/v2\/types\/docs"}],"author":[{"embeddable":true,"href":"https:\/\/www.curiaweb.ch\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.curiaweb.ch\/en\/wp-json\/wp\/v2\/comments?post=22416"}],"version-history":[{"count":1,"href":"https:\/\/www.curiaweb.ch\/en\/wp-json\/wp\/v2\/docs\/22416\/revisions"}],"predecessor-version":[{"id":22418,"href":"https:\/\/www.curiaweb.ch\/en\/wp-json\/wp\/v2\/docs\/22416\/revisions\/22418"}],"wp:attachment":[{"href":"https:\/\/www.curiaweb.ch\/en\/wp-json\/wp\/v2\/media?parent=22416"}],"wp:term":[{"taxonomy":"doc_category","embeddable":true,"href":"https:\/\/www.curiaweb.ch\/en\/wp-json\/wp\/v2\/doc_category?post=22416"},{"taxonomy":"doc_tag","embeddable":true,"href":"https:\/\/www.curiaweb.ch\/en\/wp-json\/wp\/v2\/doc_tag?post=22416"}],"curies":[{"name":"WP","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}