Yeah, so this is kind of a bug in FlyCamAppState but the cause was that you had input disabled. This may have frustrated you later when you tried to access InputManager and found it was not there.
Note: I’ve fixed the “bug” in FlyCamAppState but only in trunk and not in the 3.0.x branch. It only occurs if you have input completely disabled for the whole app and in that case it doesn’t even make sense to have a flycam in the first place.