Unable to load featurelist 'default': Permission denied

Issue :

The following error occurs while trying to login to any webmail client :

Internal Server Error
Unable to load featurelist ‘default’: Permission denied

Fix :

1. Log in to the server via SSH as ‘root’.
2. Open the file /etc/cpupdate.conf and make sure CPANEL=manual.
3. Run /scripts/upcp –force

This should fix the issue!