Finder gets "stuck" on top

Question

I've been running into an issue with my MBP recently that is driving me insane.
Occasionally, finder will get "stuck" as the dominant process and I am unable to use the keyboard for any other application. I can click on another application and it will show in front but up in the upper left it will still say Finder. I can usually log out and log back in to get it working properly but it's annoying and time consuming.
This started happening several months ago and seems to be occuring more frequently over the past few weeks. The only connection I can make is that it always happens after I open my MBP after returning to my office after teaching my lecture. When I lecture I connect my MBP into the projector through a cable that runs into a computer system where I then touch "Laptop - send to projector". When I finish my lecture I disconnect the cable, everything works fine and I'm able to run programs and use the keyboard. The problem seems to be happening right after when I close my computer and walk back to my office. When I open it back up, that's when it gets stuck...not every time, but enough to be annoying. It doesn't seem to happen when I directly connect into projectors in my other classroom on other days so I'm assuming it's something with the connection into this so-called "smart" high-tech classroom computer system.
Does anyone have any suggestions as to how to fix this or prevent it from happening?

Answer 1

Try a restart.
Do a backup, using either Time Machine or a cloning program, to ensure files/data can be recovered. Two backups are better than one.
Try setting up another admin user account to see if the same problem continues. If Back-to-My Mac is selected in System Preferences, the Guest account will not work. The intent is to see if it is specific to one account or a system wide problem. This account can be deleted later.
Isolating an issue by using another user account
Try booting into the Safe Mode using your normal account.  Disconnect all peripherals except those needed for the test. Shut down the computer and then power it back up after waiting 10 seconds. Immediately after hearing the startup chime, hold down the shift key and continue to hold it until the gray Apple icon and a progress bar appear and again when you log in. The boot up is significantly slower than normal. This will reset some caches, forces a directory check, and disables all startup and login items, among other things. When you reboot normally, the initial reboot may be slower than normal. If the system operates normally, there may be 3rd party applications which are causing a problem. Try deleting/disabling the third party applications after a restart by using the application un-installer. For each disable/delete, you will need to restart if you don’t do them all at once.
Safe Mode - Mavericks   also Yosemite
Safe Mode - About