Security update 2016-004 causing the finder to relaunch frequently?

Hello there, jusbajan!

Thanks for reaching out to the Apple Support Communities! It sounds like you are having an issue with Finder not working properly on your iMac. I know how important it is to be able to use Finder and have it work properly at all times. I would suggest booting the computer into safe mode to see if the issue is happening there. Check out this article here: Try safe mode if your Mac doesn‘t finish starting up. Even though the Mac is starting up correctly, safe mode will help eliminate startup issues that could cause issues like what you are having with Finder.

Starting up in safe mode

Follow these steps to start up into safe mode.

1. Start or restart your Mac.
2. Immediately after you hear the startup sound, press and hold the Shift key.
3. Release the Shift key when you see the Apple logo appear on the screen.

After the Apple logo appears, it might take longer than usual to reach the login screen or your desktop. This is because your Mac performs a directory check of your startup disk as part of safe mode.

To leave safe mode, restart your computer without pressing any keys during startup.

If you don't hear a startup chime after pressing the power key, see what to do if your Mac won't turn on.

If you're using FileVault

If your startup disk is encrypted with FileVault, you can still hold down the Shift key immediately after powering on your Mac to start up in safe mode. You might be prompted to log in twice as part of this process – first to unlock the startup disk, and a second time to log into the Finder. You can let go of the Shift key after you see the first login screen.

If those steps don't help, check and see if the issue happens with a Test user by following this article: How to test an issue in another user account on your Mac​. The Test user will let you see if the issue is user specific or system wide.

Cheers!

Do you have Google Drive installed?

Finder – Fix Google Drive Problem

Might be a corrupt .plist.

Do a backup, preferably 2 backups on 2 separate drives.

Go to Finder and select your user/home folder. With that Finder window as the front window, either select Finder/View/Show View options or go command - J. When the View options opens, check ’Show Library Folder’. That should make your user library folder visible in your user/home folder. Select Library. Then go to Preferences/com.apple.finder.plist. Move the .plist to your desktop.

Re-launch Finder by restarting the computer and test. If it works okay, delete the plist from the desktop.

If the same, return the .plist to where you got it from, overwriting the newer one.

Thanks to leonie for some information contained in this.

You are welcome.

Thanks Jusbajan for posting this question and thanks to all those that replied with solutions. I had the same problem on my iMac (2.7 GHz Intel Core i5) running OS X Mavericks 10.9.5. The finder would barely run and folders would freeze up every few minutes as described. I deleted the "com.apple.finder.plist" file from Preferences and rebooted in Safe Mode. The problem persisted and didn't go away completely until I deleted Google Drive. Strange that there were no problems with Google Drive until this latest security update but I don't use the app very much so I can live without. Anyway, this problem was driving me nuts for the past couple of weeks and I'm very pleased that everything is back to normal. Thanks again! 🙂