I’ve been having the following iTunes error for a while now.
Generally I ignore it and reopen iTunes. It’s not as though I even have a Sonix SN9C201 Webcam anyway….
After a little bit of internet research it would appear that the problem is when installing Skype that app throws a Sonix SN9C201 Webcam file into ~/Library/Quicktime and if you delete that file, that fixes the problem.