On WordPress sites a common error message is “There has been a critical error on this website. Please check your site admin email inbox for instructions”.
This is almost always due to a PHP compatibility issue where a plugin or theme is throwing an error and the site cannot be loaded.
The video below walks through how to troubleshoot and solve this problem on our WPAlpha hosting platform. A similar approach can be taken for any other hosting.
Broadly the first step is to check the error logs on the server and trace down the plugin causing the issue and disable it.
In the video, the SeedProd Coming Soon Page plugin was the root cause of the problem. The plugin was nearly 3 years out of date and not compatible with PHP 8.0 hence the problem.