Students can not log in

As an administrator, I have inserted and enrolled student users with the help of “data admin” module. Everything went fine but while I went to log in with a student username and password it shows:
“You do not have sufficient privileges to login.”
I can’t understand what is wrong here…

The problem is solved… It’s the all_roles field under system admin> system access that was not set.

Ah, good catch. I’ve taken a look and will update the Data Admin module so that this is a required field, which should help prevent importing users without this field in the future. Thanks!