This worked to re-enable – “re-Zoom” 
– the mimoLive virtual camera as a source to Zoom 4.6.11 on my Catalina system. For me, it was preferable to running an older version of Zoom. But I will have to repeat the command for each Zoom upgrade.
codesign --remove-signature /Applications/zoom.us.app/
source: https://medium.com/@dkiesow/how-to-fix-the-virtual-camera-function-in-zoom-mac-only-9872a6d9ea5