On a serious error, WordPress shows a blank white page, the message There has been a critical error on this website, or a 500 error. Most often the cause is a plugin, a theme or an unsuitable PHP version. Work through the most likely causes first.
1. What you changed last
Think about whether you updated or installed a plugin or theme before the error, or changed the PHP version. Undo the last change.
2. Find the error
Turn on debug logging following the guide PHP errors and debugging. In the file wp-content/debug.log you will see which plugin or file causes the error.
3. Deactivate plugins via FTP
If you cannot get into the admin area:
- Via FTP, rename the wp-content/plugins folder to plugins_off. All plugins will be deactivated.
- Try opening the website and the admin area.
- If it works, restore the original folder name and activate the plugins one by one until the error appears.
4. Switch to the default theme
Via FTP, rename the folder of the active theme in wp-content/themes. WordPress will switch to the default theme.
5. Restore .htaccess
Rename the .htaccess file to .htaccess.bak. After logging in to the admin area, open Settings > Permalinks and save, and the file will be created again. For more about the file, see .htaccess.
6. Memory, space and PHP version
- If the message contains Allowed memory size exhausted, see PHP memory limit.
- Check whether your hosting space is full, see How to choose a package.
- If the error appeared after switching PHP, go back to the previous version and update the plugin or theme.
It did not help
Restore the website from your own backup (see Updates and backups), or write to us and send the contents of the error log.