If you are having the problems described in this thread, what was the last version of PokerTracker 4 you upgraded from? Was it the most recent beta, or did you upgrade from 4.02.x stable? Also please submit your logs are requested by WhiteRider above. To do this, pPlease enable logging (Configure > Options) and restart PT4. Play a few hands at a single table. If you see the problem please take a screenshot and attach it to a Support Ticket along with the PokerTracker4.log file from C:\Users\yourname\AppData\Local\PokerTracker 4\ (which you can access from the PT4 File menu) and the hand history file for the session.
Tutorial: Reporting a problemFor those of you requesting a new update - we need your logs to determine what happened to your computer, an update may not be needed, we don't know what the problem is yet because this issue is not affecting everyone universally. Thanks in advance for your help.