I tried resetting preferences on exit and was able to edit one photo, but then when I saved my select and mask settings, I got the "could not apply the workspace because of a program error" message again. I do NOT want to change my select and mask settings for EACH photo I edit. I did a product shoot and have 80 photos to edit!
Reset Workspace preference then restarted. Didn't work.
You've reset the workspace and preferences?
From Adobe on how to reset preferences:
To restore preferences quickly using a keyboard shortcut: Press and hold Alt+Control+Shift (Windows) or Option+Command+Shift (Mac OS) as you start Photoshop. You are prompted to delete the current settings. The new preferences files are created the next time you start Photoshop.
If that doesn't work, have you tried simply uninstalling and reinstalling? This might seem silly, but sometimes that helps