This has been happening to me for some time with Caja. Sometimes, it enables file selection (same thing when I select files while holding the Control key). It goes into this weird state where I can't even open up an another app.
Is there a shortcut to trigger this behavior is is it a bug in Caja?. Only solution I got is restart the system and it's so annoying.
Sounds like Xorg (the display server) gets stuck with Caja, it is a weird state where the mouse pointer moves around but it's somehow got "locked" to a program, so clicking doesn't work, but the keyboard should.
Instead of restarting the system, you should be able to restart Caja by pressing Alt + F2 and typing:
caja -q
or:
killall caja
followed by Enter.
Though I'm not sure what exactly is triggering this issue - are you selecting a bunch of files and dragging the selection to another window, and the mouse cursor gets stuck?
Mouse cursor doesn't get stuck. It's the Caja window itself. Also, it's happening inside a single window. I can move mouse cursor freely but all it does is select files (keep selecting files like i'm holding control)
This is exactly what lah7 was talking about. You can follow his advice.