A weird problem started happening on my system in recent days (can't remember exactly). When I launch Activity Monitor, mouse pointer freezes and can't move normally until I kill Activity Monitor by using keyboard.
It works OK otherwise.
OS X version is 10.11.6 (15G1108)
. I have also installed SmoothMouse.
EDIT:
I removed SmoothMouse by issuing command brew cask zap smoothmouse
, now the mouse cursor can move while Activity Monitor is opened, but Activity Monitor itself is still freezing and is barely usable.
Best Answer
This problem went away after I rebooted the system. (It was running for several weeks without rebooting before).
This clearly indicates that OS X just can't handle long uptime, because Apple cares more about bells and whistles than stability. :(