You are unable to log in to the user account “user_name” at this time
It was Little Snitch :-(
I found the solution here https://discussions.apple.com/thread/4676595?start=0&amp;tstart=0
First I put LS into silent mode, allowing all connections, but did not help. Then I disabled it completely and login worked.
Then at the new user login it reported that there were connections attempts during logon, I examined these, set them to permanent enabled LS and it works fine.
Here are the rules appearing on the net logon account:
NethAuthSysAgent allow outgoing connection to domain domainname (where the domain name is the domain you are logging into)
NethAuthSysAgent allow outgoing connection to ipaddress (where the ipaddress is the address of your OS X server, hosting the OD I guess)
opendirectoryd allow outgoing connection to ipaddress (where the ipaddress is the address of your OS X server, hosting the OD I guess)
I hope this helps some one out there