Occasionally, such as when migrating a website to a new hosting environment or setting up a server for a new site, a 500 Internal Server Error may occur, accompanied by log entries like the following:

AH00526: Syntax error on line 120 of /etc/apache2/sites-enabled/010-website.conf: Invalid command ‘AuthGroupFile’, perhaps misspelled or defined by a module not included in the server configuration Action ‘configtest’ failed. The Apache error log may have more information.
or 
[Wed Jan 01 17:15:22.524405 2023] [core:alert] [pid 2407241] [client 127.0.0.1:38520] /home/domains/domain.com/.htaccess: Invalid command 'AuthGroupFile', perhaps misspelled or defined by a module not included in the server configuration

 

The error occurs due to the absence of the Apache module authz_groupfile. You can install it by running the following in the server console:

sudo a2enmod authz_groupfile

And restart apache:

systemctl restart apache2

If it's not possible to install authz_groupfile, you can resolve the error by removing from .htaccess the lines starting with

AuthGroupFile ....

But you should make sure that authorization is provided by other methods or is not needed at all!