1. After changed the authentication in UMP such as Control Panel, users can not login via UMP login console.
Tried to change the portal-ext.properties to screen name, still fails.
2. After changed the log on method from Screen Name to UserID and now locked out of the UMP. Not even the superuser account can log in.
The change was made in UMP under the Control Panel ->Settings -> Administration
Delete the rows from portlet preferences.
To do this, since UMP was down and we had no access to SLM, we used SQL Management Studio.
Once deleted we were able to login again.
Apparently the GUI doesn't delete from portlet preferences when you use it to switch between login authentication methods.