hello,
I was search about a solution to this problems because I have the same problems.
but the problem not on Php.ini
the problem is too simple
you need to change the register script with a new one
because this one is old for old version 7.0 or 7.3 I don't know exactly
but if you verify the script in index.php source you will find that the string seach on "Accounts" but the Auth Database has "Account" without S
beside that if you see defrence between Database content and register page content.
and sorry because I'm still search about a solution
I just want you to know the probel where to not try the script