I have a newly installed Windows 2012 R2 server and I just added the Windows Server Update Service role. After the install completed, I launched the post-installation task.
The post install configuration failed. I reviewed the .tmp file to see what actually caused the task to fail.
CreateDefaultSubscription failed. Exception: System.Data.SqlClient.SqlException (0x80131904): Login failed for user USERID
The user is the computer name of the WSUS server.
I launched SQL Management Studio and located the user referenced in the log file.
After looking at the roles assigned to that database user, I then checked the SYSADMIN server role members and noticed the user mentioned is not listed.
I added the computer name as a member and re-ran the post-installation task.
That did the trick and the post deployment configuration completed without error.
I’m still testing to see if I can assign the computer a more restricted role other than sysadmin, and I haven’t found any documentation on it, but I’ll keep searching. Maybe I’ll tweet Lawrence Garvin.