turns out this the permissions on my home directory have been set to 775, which gdm doesn't like. this however is an extremly confusing error message.
** Changed in: gdm (Ubuntu) Status: New => Invalid -- gdm always uses Fallback for UserAuthDir https://bugs.launchpad.net/bugs/123697 You received this bug notification because you are a member of Ubuntu Bugs, which is the bug contact for Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs