In order to log in one needs a valid home directory (and valid content). You don't provide enough information to determine what was done:
- Did you copy the home directory,
- Did you move it,
- Did you change anything else
- Do other user also have this problem.
I can only give you some general advise at this point: Restore the home directory to what it was or remove the user completely and create a new user (this might help:
Ubuntu User Management).
