Hi,
Sorry for my late reply try safe mode as follows turn off the Mac and leave for a few mins.
- Now restart your Mac.
- Immediately after you hear the startup sound, press and hold the Shift key.
- 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.
If this has worked then you should see the apple icon in top left of screen put mouse on it and choose force quit then select finder.
Once done to leave safe mode, restart your computer without pressing any keys during startup.
If this has worked you may not see finder in the dock so go to /System/Library/CoreServices/Finder.app