500 error on front-end but not on admin

My problem had to do with file permissions. Even though it looked like the permissions were correct, the index.php in the root had the permission set to 644, instead of 664. Once I changed the permission the front-end loaded. It’s a bit odd that of all files in the root, the index is the only one with the wrong permission.

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)