PokerStars released client update version 7. TableScanner is currently only compatible with version 6. To use TableScanner with PokerStars you will need to revert to their v6 software:
A) Open PokerStars and click Settings:
B) Click Global > Revert to PokerStars 6 option (1) then click the Revert Software button (2)
If you want to be notified when v7 support is added for TableScanner please send an email to email@example.com and include "Notify Me When HM-7712 Is Resolved" in the subject line and body of the email.