I tried to login to the Workspace and supplied the UserName, Password -Both from K2Users table IN SQLUM- i also supplied the "Security Label" which is K2SQL.
It keeps telling me that " Your login attempt was not successful. Try again. "
To my knowledge the SQLUM was built to work like an ASPNetMembershipProvider. It might be required to properly register a user before you will be able to log in.
Use the CreateUser Stored Procedure on the K2SQLUM database to create a new one. After creating one try to log in with this new user. I don't think there is a working user interface for this from workspace.
I have seen some pages in the /workspace/profile/ virtual folder but I'm not sure if they will work.
To troubleshoot the issue further, maybe check the K2 logs, they might have a bit more information.
Hope this helps!
Many Many thanks Mr. Johan