When a user gets kicked out of the Abacus program with no error message or an error message in TSFUNCT, this is a problem with the link to Timeslips.
First make sure that the user is able to get into Timeslips. If they are not able to open the Timeslips program, then they will need to call them up to get their errors fixed.
If the user is able to get into Timeslips make sure that they do not have more licenses of Timeslips then they do of Abacus. If they have more users of Timeslips have them exit out of the extra machines and then see if they get the error message. When you open Timeslips it uses a license for Abacus which will consume one Abacus Fortress License for each user that opens Timeslips.