Have you seen an error message in a Drupal site like this?
When you are building or modifying a Drupal site, the error above can sometimes appear and catch us in unexpected situations, but there is nothing much you can do. “Try again later” is not going to help. What will you do?
There is not much you can do about it, because there is not enough information to go further. By default, Drupal is configured not to display error messages. To find out what caused the errors, the error message display options require to be turned on first.
In this tutorial, you’ll learn how to turn on error display to help you debug.
WARNING: It’s important not to display error messages on a production site. The error messages could display sensitive information such as paths or server level user accounts.