If u are using cpanel u need to add user to db after creating a user
Maybe u didn't do that
msk19994 Reviewed by msk19994 on . Start up error Please help me with this: Due to the following errors, the install/upgrade can not continue: Database connection failed due to unexpected error: (1044) Access denied for user 'b7_11359603'@'%' to database 'b7_11359603' Please ensure that the database and server is correctly configured and try again Rating: 5