Symfony Expected argument of type "string", "null" given

In Symfony, if you encounter an error message stating "Expected argument of type 'string', 'null' given", it means that you are passing a null value instead of a string where a string is expected.

To resolve this issue, you need to make sure that you are passing a valid string value instead of null to the function or method that requires it. You can do this by checking if the value is null before passing it, and handle the situation accordingly.