Thanks so much for your response Liviu . I downloaded the installer again and ran repair. This seemed to fix that problem, as the files are now resident in the appropriate directory.
I am now experiencing this issue. I get the same error as the original author (with a slightly different file path due to the later version). I recently updated to version 20.5. When I look at the directory specified in the error message, I do not see a "ExternalUI.exe" file at all. Any id...