{"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-error-logs\/\">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. Do not restore a backup immediately<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A backup is very important for restoring a website. However, it should not automatically be the very first step for every critical error.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For example, if only a newly activated plugin is causing the error, deactivating it can be much faster and cleaner than completely restoring an older version of the website.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A backup restore can also overwrite newer content, orders, form submissions, or other data created since the backup time.<\/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> If possible, determine the cause first. A complete restoration is especially useful if files or data have been damaged or if a controlled return to a known working state is required.<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\">21. When a backup is still the right solution<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A restoration can be useful if, for example:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>numerous files were damaged<\/li>\n\n\n\n<li>a failed change cannot be cleanly undone<\/li>\n\n\n\n<li>several components were changed simultaneously<\/li>\n\n\n\n<li>malware or tampering is suspected<\/li>\n\n\n\n<li>a known working anchor is required<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">With dynamic websites such as WooCommerce stores, it is necessary to check particularly carefully which data would be overwritten by a restore.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">22. Consider cache after troubleshooting<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Even if the underlying cause has been resolved, a cached error page may still be visible in some circumstances.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Depending on the website, different cache layers can be involved:<\/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 or page cache<\/li>\n\n\n\n<li>CDN or Proxy<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">However, do not reflexively clear cache systems as a first diagnostic step. A PHP fatal error will not be fixed by clearing the browser cache.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">23. Is a white page always a WordPress error?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">No.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A seemingly blank page can also have other causes, for example:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>CSS hides content<\/li>\n\n\n\n<li>JavaScript prevents the expected rendering<\/li>\n\n\n\n<li>an empty template output<\/li>\n\n\n\n<li>a cache delivers faulty content<\/li>\n\n\n\n<li>an external dependency is causing issues<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Therefore, it is important to distinguish between an actually empty server response, a PHP fatal error, and a merely visually empty page.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">24. Critical error or HTTP 500?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Depending on the server and WordPress configuration, a critical PHP error can also manifest as an HTTP 500 error.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A <strong>500 Internal Server Error<\/strong> however, it is more general and can have other causes besides PHP errors.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If your browser explicitly reports a 500 error, you can find targeted diagnosis in the article <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. Critical error or website completely unreachable?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">If no connection to the website can be established at all, WordPress is not necessarily the cause.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The following areas can also play a role:<\/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>web server<\/li>\n\n\n\n<li>SSL<\/li>\n\n\n\n<li>Hosting<\/li>\n\n\n\n<li>Network<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">For this case, we are using a broader diagnosis in the article. <a href=\"\/en\/help\/wordpress\/wordpress-website-not-accessible\/\">WordPress website not accessible: systematically check causes<\/a>.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">26. Website is working again \u2013 is the issue resolved with that?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Not necessarily.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For example, if you have deactivated a plugin and the website works again, you have initially eliminated the symptom.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">After that, you should also clarify:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>why the plugin caused the error<\/li>\n\n\n\n<li>whether a compatible version is available<\/li>\n\n\n\n<li>whether the plugin is still needed<\/li>\n\n\n\n<li>whether there is a conflict with another component<\/li>\n\n\n\n<li>whether there are any further errors in the log<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">A critical bug should not be \u201eresolved\u201c by forgetting the root cause as soon as the homepage reappears.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">27. Disable debugging again after troubleshooting<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">If you have enabled WordPress debugging for diagnostics, you should reset the settings to a state suitable for a production website once troubleshooting is complete.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In particular, detailed error messages should not be permanently displayed publicly.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Generated log files should also be monitored regarding content, storage space, and access.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">28. Sequence for systematic troubleshooting<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">When WordPress shows a critical error or a white page, you can generally follow this order:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Stay calm and do not make random changes.<\/li>\n\n\n\n<li>Check what was changed immediately before the error.<\/li>\n\n\n\n<li>Check which areas of the website are affected.<\/li>\n\n\n\n<li>Check administrator email and spam folder.<\/li>\n\n\n\n<li>Use Recovery Mode if available.<\/li>\n\n\n\n<li>Investigate recently modified plugin or theme.<\/li>\n\n\n\n<li>Check the PHP version, especially after a change.<\/li>\n\n\n\n<li>Analyze error logs.<\/li>\n\n\n\n<li>Enable WordPress debugging in a controlled manner when needed.<\/li>\n\n\n\n<li>Check the memory limit if the log indicates so.<\/li>\n\n\n\n<li>Fix the root cause specifically.<\/li>\n\n\n\n<li>Test frontend and admin area completely.<\/li>\n\n\n\n<li>Check debugging settings again.<\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading\">29. What you'd better not do in the event of a critical error<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>do not delete WordPress files indiscriminately<\/li>\n\n\n\n<li>do not delete multiple plugins at the same time without documenting the cause<\/li>\n\n\n\n<li>do not modify the database immediately<\/li>\n\n\n\n<li>do not increase arbitrary PHP values without understanding the error message<\/li>\n\n\n\n<li>do not switch to an old PHP version without checking first<\/li>\n\n\n\n<li>do not change all file permissions<\/li>\n\n\n\n<li>do not immediately restore an old backup over a current dynamic website<\/li>\n\n\n\n<li>permanently display non-detailed PHP errors publicly<\/li>\n\n\n\n<li>don't forget the old working configuration before you make changes<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">30. What information helps support?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The more precisely the initial situation is described, the faster a technical error can usually be isolated.<\/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>exact visible error message<\/li>\n\n\n\n<li>Time since the error has been occurring<\/li>\n\n\n\n<li>last change before the error occurred<\/li>\n\n\n\n<li>most recently updated plugin or theme<\/li>\n\n\n\n<li>PHP version used<\/li>\n\n\n\n<li>whether the frontend and admin area are affected<\/li>\n\n\n\n<li>relevant entry from the error log<\/li>\n\n\n\n<li>whether a WordPress recovery email has arrived<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">If an error log is available, the relevant section with a timestamp should be submitted. A complete log with thousands of old messages is often less helpful for a targeted diagnosis.<\/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\">If your WordPress website shows a critical error or a white screen at CURIAWEB and you cannot clearly identify the cause, support can help narrow down the technical issues within the hosting and WordPress environment.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Contact support especially if:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>frontend and admin area are no longer accessible<\/li>\n\n\n\n<li>you cannot classify the error message in the log<\/li>\n\n\n\n<li>the error occurred after a change in the PHP version<\/li>\n\n\n\n<li>a memory or PHP error is displayed<\/li>\n\n\n\n<li>if you are unsure, before you manually change files or settings<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Do not send passwords unsolicited. Instead, describe as precisely as possible when the error began and what change was made immediately beforehand.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Summary<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A white WordPress page or a critical error message often indicates a serious PHP error. Typical causes include plugins, themes, custom code, PHP incompatibilities, or an exhausted memory limit.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">First, check what was changed immediately before the error. Then, check the administrator email for a message regarding WordPress Recovery Mode and investigate suspicious plugins or themes.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If the cause is not obvious, you should use error logs instead of changing settings on suspicion. File paths and error types often provide concrete clues as to which component is involved.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A systematic diagnosis is more important here than a sequence of changes as rapid as possible: identify the cause, fix it specifically, test the website, and then reset temporarily activated debugging measures.<\/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":"2026-10","word_count":3257,"total_views":"28","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}]}}