Might be a permissions type issue preventing you accessing the data. Have you loaded the apps in the correct order.
1 - Load PokerTracker
2 - Click Start Getting Hands
3 - Open Stars
4 - Play
Another thing to check is if both PokerTracker and PokerStars are running as admin. To configure an application (e.g. PT4 or your poker site software) to Run As Administrator right click the icon that you use to launch it and choose the "Run As Administrator" option for both applications and then open in the order stated above.
If you are still having a problem then you could try reinstalingl PokerTracker in case something got corrupted in the most recent update since you mentioned it was a problem after a recent update. If none of the above works please open a Support Ticket
and report your problem
while noting what tournament type you are seeing the issue on and one of our technicians can assist you in resolving the matter