Compatibility issue caused by plugin: Your newly added Plugin may be a mismatch to WordPress environment. Experts recommend two different ways to solve this issue. First, you can go to the administration screen and then deactivate all the Plugins. After you are done with deactivation of all the Plugins, try to reactivate them one by one.

But sometimes you may find that you can’t access the administration screen. Then you need to try to login to your website through FTP server. After you are done with the login credentials, try to find out the Plugin folder and rename it. Once, you rename the Plugin folder all the Plugins will get deactivated.New theme created by you can be a reason: Most of the times this error occurs due to a newly created theme or a newly created site in your WordPress network. To resolve this issue, you can either login to administration screens to activate the default theme that is WordPress ‘Twenty Sixteen Theme’ or else if you find it difficult to login to the screen you may try to login via FTP file server and access the theme created by you then you can change the name of the theme.

Theme directory can go missing or renamed: This error may occur when a developer creates something in WordPress and clones it, during the process many times it happens like that a theme or a directory goes missing or renamed. And this cause an error. There are several ways to solve the issue. You may switch or edit the theme or rename you directory to restore this problem.