In launching Pd or using Gem patches, this never happens. And it's just never available.
It never happened because the camera was no longer accessible to Gem.
To clarify:
Gem 0.93 did not stop working, only those plugins which used Quicktime stopped working as Quicktime is no longer shipped with macOS 10.13+, ie. pix_video, pix_film, etc.
Gem 0.94 solves this by introducing replacement plugins which use the newer AVFoundation macOS framework.