It occurred constantly (repeatedly) ever since I updated to 191126. I tried loading other scripts and disabling Wi-Fi but that didn’t seem to change anything. I decided to disconnect the powered USB hub, which finally made that message stop appearing.
Attached to that hub is a walnut 128 Grid, the latest Arc and a Mio MIDI interface. I’m assuming this has something to do with the MIDI interface, not the Grid or Arc.
Edit: Sorry, my hub isn’t very easy to get to - it is stored under the stand for my Grid & Arc, which is surrounded by others. Seriously limited desk space over here! I decided to check anyway (for science) and am able to confirm now that the error doesn’t appear after disconnecting the Mio. I don’t think the Mio is defective, so it may be something that changed with this update.