Unable to test movie after saving

I am new to Animate and been challenged by not being able to "test movie" for projects.  For troubleshooting, I removed Preferences and later uninstalled and reinstalled Animate 2021.  This last step did help me test the movie until I saved the project.  Immediately after that, I could not longer test the movie.  I am working on a Mac with OS 10.15.7.  Error message is "output directory could not be found.  Please update it and try again." Any advice on how to get past this problem would be appreciated.