Preview app doesn't open since I installed MACOS Catalina

Question

import PIL
img = PIL.Image.new("RGB", (100,100))
img.show()

The error message:

FSPathMakeRef(/Applications/Preview.app) failed with error -43.

Answer 1

Following from Sean True's answer, an even quicker but temporary fix is to simply make a symbolic link to Preview.app in the old location. In the terminal run

ln -s /System/Applications/Preview.app /Applications/Preview.app

This fixed the problem for me.