The file ufarcst.dat in the main unForm server folder contains the "remembered last page" for a user's archive browser session.
If you experience inordinately long load times of the remembered page or it appears to hang upon logging in, the administrator can delete that file at the server OS level to have the remembered page go away and free-up the user's browser session.
The file contains information for all users, so all remembered pages will be cleared for all users, which should not be a problem as the remembered pages are not more than a time saver or a tickler.