Finder cannot be opened and crashes with exc_bad_access report and crash type „Code signature invalid“

In this article I show you how to fix your Mac when Finder doesn’t open, desktop symbols aren’t showing and no programms will open up.

I’ve encountered this error after upgrading my RAM on my iMac. Somehow, an update process must have been broken while upgrading the memory, rendering the Finder and my Mac useless.

To fix the problem I tried everything from PRAM reset to SMC reset without any solution. Even starting the Mac in safe mode didn’t solve the problem.

The Finder Icon

Finally, I fixed the problem by reinstalling the OS on the hardrive on top of the existing installation. By doing so, no data from the current installation will be lost, but system functions will be reinstalled in case of them being faulty.

To reinstall the OS on top of your installation, press the CMD-key and the R-key simultaneously while booting up the system.

The whole process will take some time (about 50 minutes in my case) and the Mac will restart several times. Progress bars will disappear without warning during the process and the reboot behaviour made me think, that something was wrong, as the Mac powered off a few times without warning and in short intervals.

But at the end, everything was fine and the problem was repaired. Finder and all other programs were restored and could be opened again.