You can force a Paratext shutdown with this program: C:\Program Files\Paratext 9\ParatextForceShutdown.exe
After Paratext has shut down you should use a Reset to open Paratext. This will close all of the windows and reset basic Paratext settings. It will not delete any data. The instructions for a reset can be found at: https://paratext.org/?s=reset
When Paratext opens, go to the Main menu > Help > Check for Updates (you may need to expand the menus) and allow Paratext to update.
Once you have done these steps you should be able to continue working.