UPDATE 2021-01-23
I managed to get hold of a Big sur Mac and updated the DMG package, now it should work.
Note: will not work on Apple Silicon (M1)
Grab the latest release here: https://github.com/colin-campbell/firestudio-catalina/releases/latest
(Silent) Video Demonstration:
UPDATE 2020-07-07: I have released a "point and click" installer DMG file, signed by me and notarized by Apple, to make things easier for people not comfortable with using Terminal. Get it here:
https://github.com/colin-campbell/firestudio-catalina/releases/latest
Note: this does not contain any Presonus code, it just downloads, extracts and installs the driver and Universal Control v.1.7.6 in a way that is Catalina-compatible. Just open the DMG and start the installer.
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Universal Control v3.2.1.57677 DMG file contains a signed firewire audio and MIDI driver package which is an identical version to the one in old UC 1.7.6 package. The difference is that the installer simply installs the kext in the correct location for 10.15 Catalina.
You will get no support of course, but the kext is as safe as it ever was to use and you will have coreaudio/midi support, but no UC panel.
I am trying to figure out what makes the 1.7.6 panel segfault on Catalina, if I find a workaround I will make it public.
EDIT:
Ok I bit the bullet and made an install script that should work, at least for 10.15.
It downloads and installs the new Firewire driver, then downloads Universal Control v1.7.6, extracts the package and installs the Control Panel and interface drivers manually. This is working perfectly for me on Catalina 10.15.4 - your mileage may vary.
The script and instructions for use are located here:
https://github.com/colin-campbell/firestudio-catalina
It is highly recommended you make a backup and remove any old drivers before running this script! I accept no responsibility if your computer explodes or you get infected with COVID-19! Use at your own risk and read the script before you use it.
It is unfortunate that PreSonus don't spend the 10 seconds it would require to repackage and sign the old Control Panel to be 10.15 compatible, because it works perfectly fine - only the installer is incompatible.
Good luck!