This can be caused by a faulty plug-in.
1. Go back to a php version that the website works.
2. Then in WordPress de-activate all the plugins via Dashboard->Plugins menu button on the left.
3. In case you are unable to reach WordPress dashboard.
You can also manually de-activate the plugins via an FTP editor, like FileZilla software. Go to your server folder where WordPress is installed , then
in the /wp-content/ the plugins folder is present.
How to: De-activating all the WordPress plugins manually:
In /wp-content/ folder temporarily renaming the plugins folder to for example plugins-off disables all the WordPress plugins. Later you can remame it back to its original name. Then activate them one by one in the WordPress dashboard, as described in step 5.
4. Try updating to the desired php now and see if the problem is solved.
5. To find which plugin is causing the problem, activate the plugins one by one.
If you have renamed the plugins folder as explained in step 3, remember to rename it to the original plugins name first, before activating the plugins in WordPress dashboard.
Extra info.
One of the plugins that we had which often cause this issue is is Slider Revolution plugin.
If you have updated to PHP 7 or above and are experiencing a critical error in WordPress, there are a few steps you can try to solve the issue:
- Check the error message: The error message may provide clues as to the cause of the issue. For example, if the message mentions a specific plugin, you may need to disable or update that plugin.
- Check your theme: If the error message does not provide any clues, you may need to switch to a default WordPress theme to see if the issue is with your current theme.
- Check your plugins: If the issue is not with your theme, you may need to disable your plugins one by one to see if any of them are causing the issue.
- Check for compatibility issues: If you have recently updated to PHP 7 or above, it is possible that some of your plugins or themes are not compatible with the new version. You may need to update or replace these plugins and themes to fix the issue.
- Check for a corrupted .htaccess file: The .htaccess file in your WordPress installation may be corrupt. You can try renaming the file to see if this fixes the issue.
- Contact your hosting provider: If you have tried all of the above steps and are still experiencing the issue, it is possible that the problem is with your hosting environment. In this case, you may need to contact your hosting provider for further assistance.
