OSX Lion - Stuck in Drag mode and mouse click events are not going through. Can I manually generate a mouseup event?

Solution 1:

I got exactly the same issue, but the internet resolves nothing. It seems that when I restart my MacbookPro, it "could" go away. When I close all my apps, I get more successful results. When Lion loads the apps that were open when I restarted, I get a "sticky" drop scenario more consistently. Not hardware related, think it could be a Lion glitch.

Update: https://discussions.apple.com/thread/3191768?start=0&tstart=0

Quick fix for the drag and drop: sleep and wake your MacBook. For whatever reason everything is fixed when I do it. But if I restart, I lose it again. It must be some type of startup issue.

Solution 2:

If you go into "Trackpad" in "System Settings" and toggle various options for gestures, clicks, and drags.. it will "unlock". Annoying, yes. Requiring a restart, no.

Also, sometimes a key on the keyboard gets stuck. Bang on the keys (or equivalent) to make sure that's not causing your grief.

Solution 3:

I experienced this problem and dealt with it for a month or two by putting the machine to sleep every time I noticed it. This is only a temporary fix, however, as the problem returns on a restart. Not usually a problem, but makes apps like Photoshop neigh unusable!

I was pretty sure Air Display (an iOS screen sharing app) was the culprit so I tried uninstalling it with AppCleaner, but the problem remained. However, this SwitchingtoMac ad confirmed my suspicion: http://www.switchingtomac.com/tutorials/osx/cant-drag-and-drop-in-os-x-lion/

A quick Finder search turned up a proper uninstall script for AirDisplay and the problem was gone. The above article outlines a number of other possible solutions as well. Good luck!