Audition problem after upgrade to Mac OS Catalina

I found a fix for this problem.   I did this:

If your MIDI devices no longer work properly after an update...

1. Empty the contents of the following two folders by moving their files into to two new folders on your desktop:
   Macintosh HD > Library > Audio > MIDI Drivers
   Macintosh HD > Users > [Your User Name] > Library > Audio > MIDI Drivers
   Note: the second location above is hidden on Mac OS X 10.7 and above.  To access it see these instructions.
   
     These are the places where third-party MIDI drivers are stored. If they have become corrupt, or they haven't been installed correctly, removing them and starting over may help.
   
   
2. Restart your computer.
3. Try your MIDI device again.
   
   

If the symptom has been resolved, you should...

• Reinstall each of these drivers by visiting the home page for the respective device manufacturers. Note, if your MIDI device is Class Compliant, it doesn't require any extra drivers to be installed.
• Find and download the latest drivers for the product(s), and install them.
• Confirm all of your devices now work properly, then trash the files you had moved from your MIDI Drivers folder to your desktop.

This also fixed similar problem with Logic Pro and Garage Band.

May I suggest that you do what it says here: Audition crashed - now what? I realise that it's not necessarily a crash in itself, but this FAQ does tell you what to do with the log files - posting them here won't really help, as the developers only look in occasionally. Sending a report to audbugs is more likely to produce a reply, especially when it comes to Macs.