Parallels

Symptoms

I am trying to access Plesk CP login page and get the error:

Warning: Unknown: failed to open stream: No such file or directory in Unknown on line 0 Warning: Unknown: Failed opening 'auth.php3' for inclusion (include_path='.:') in Unknown on line 0

Cause

This error means that Plesk cannot find needed PHP files for inclusion in the current include_path. Usually the problem is in damaged Plesk configuration files.

Resolution

Make sure that there is no php.ini file in the root directory on the server:

Rename or move it from the '/' directory if you found it, restart Plesk and try to login again.

Also check that httpsd.conf and php.ini files exist in $PRODUCT_ROOT_D/admin/conf/ directory and they have not zero size:

If you feel that these files are damaged, you can copy them from another working Plesk server, that has the same Plesk version installed. Restart Plesk and check if it works.