I think this error is OSSystemExtensionErrorExtensionNotFound, from <SystemExtensions/SystemExtensions.h>.
I see this error also when I try to deactivate my camera extension (after approving its removal with the OS' dialog), but I'm running on a laptop with a built-in, non-removable camera. Maybe the error doesn't happen if there are no cameras in the system, so my extension can be unloaded.
I don't know and don't particularly care, because in our shipping apps we never make a deactivationRequest. It isn't clear to me what that API is for - as far as the user is concerned, the driver is installed because they installed its host app and approved it.
Topic:
App & System Services
SubTopic:
Drivers
Tags: