If you see a dialog like the following when opening a composition:
QCFakePatch is a private temporary patch used when refactoring (macro-ifying or exploding macros). You normally never see it.
However: if you get an Exception dialog as a result of refactoring (this can happen sometimes if ports are published in such a way that the editor cannot complete the operation -- e.g., asking for a consumer to have outputs), you can sometimes get stale FakePatches in the composition.
It's almost always unrelated to 3rd party code.
Generally, when an exception is thrown in the editor you'll want to save your work (to a different location, so you won't destroy existing work incase the new version is now broken), quit QC, and then relaunch it. Those exceptions can leave the program in an unexpected state, which can lead to more errors as you go.