Is there a way to retrieve the pass of the ispconfig main user in mysql?
The password is in the file /usr/local/ispconfig/server/lib/config.inc.php in cleartext. Use this password from the file to reset the password in mysql in case you cahnged it.
Do not change the password in the ispconfig file as the same password is in a lot of other config files. So never try to change the password of the ispconfig user manually in mysql if you dont want to break the system.