I have a Virus TI connected to an iMac running Catalina via USB. Recently, I stopped being able to get MIDI events from the Virus keyboard. I have no idea what happened. Doesn't matter which DAW or app I use. The virus MIDI devices show up in Audio MIDI Setup and in the apps, but I get no events from the keyboards or knobs at all. I tried factory resetting the virus, different USB ports, nothing helps. Any ideas?
The latest MacOS security update decided that incoming midi events are a security threat via usb?