PokerStars released an update to their software which broke table opening in TableTracker. This will be fixed in the next release. Until then, you can do the following which will resolve the issue:
With PokerTracker closed, open "My Computer" and browse to your PokerTracker 3/Data directory.
In a default installation this is:
C:\Program Files (x86)\PokerTracker 3\Data
Locate the file named "if1.enc" and delete it. Now save the following file linked below to this same directory.http://www.pokertracker.com/misc/if1.enc
Once saved, start PokerTracker, launch PokerStars from within TableTracker and table opening should now work.