Could not connect to the database, see error message below.
Access denied for user 'khankhodadad_reg'@'localhost' (using password: YES)

I suspect your user/database name is too long - they must be 16 characters or fewer.

swordz

i have the same problem, my site name is 16 chars, so by the time i add _dbname or _user its too long. any way to fix?

Yes.

You need to set up a new site with a shorter name, and set up the databases on there. Then connect to the new databases from your old site.

swordz