If you are getting ERROR message:-
Generating Account….Account Creation Status: failed (Sorry, a mysql user with the name xxxxx already exists.)

Follow below Steps to Fix it :-
The reason for the error message is that the user “xxxxx” is not completely  removed from cache files.

1. Login to the server via SSH.

2. Search for the cPanel user in “/var/cpanel/databases/“. This will give you the files that are having the entry for the cPanel user. Now remove user from the listed files and try creating the domain.

Example: User name: test

root@server [~]#grep -Rl test /var/cpanel/databases/

An entry for the user test exists in “/var/cpanel/databases/users.db.cache“, “/var/cpanel/databases/users.db and “/var/cpanel/databases/dbindex.dbetc.
Now remove all the entry for the user “test” from these files.
Try To create Or restore the file 😀