I learned something interesting today, while fighting with my Mac over an (initially) unrelated issue. Clicking on the Finder icon in the dock suddenly stopped opening a Finder window. Similarly, clicking on the Trash icon in the dock also had no effect. Basically, I couldn’t open any Finder windows if none were already open without keyboard shortcuts.
Fortunately, I discovered that the fix is very simple.
Click on Finder in the dock. Making sure not to switch focus away from the Finder, hit Command-N on the keyboard. This will successfully open a new Finder window. Navigate to the Preferences folder in your Library folder and move the com.Apple.Finder.plist file to the Trash. Now reboot your Mac.
You’ll have to set up your Finder preferences again (icon size and spacing, items in the Finder sidebar, initial folder for new windows, etc), but it’s a very small price to pay for having a Mac with a working Finder again.
Here’s the path to the file you need to delete: