Ok, so spent some time looking in to this to see if it was related to another issue. Since I’m getting so many messages I’m fairly certain that the offending call is tick-related, which would likely make it the last one on your list:
This appears get the camera position and orientation which it then passes to the FMOD SoundSystem. To verify, if I move the camera in the editor, I can see the error message changing with new vectors (which are also not unit vectors). Sometimes it complains about the Forward vector, sometimes it’s the Up vector. The code in question looks like it should be creating unit vectors, so it’s not clear why it’s not getting them. I’ve manually checked the vector lengths and they’re way off, like 0.65 for example so it’s not a mismatch in expectations around accuracy.
However, this seems to only happen on my PC, not on my Mac, or on any of my colleague’s PCs. I’ve been trying to track down another non-sensical bug in a completely unrelated part of the code which only appears on that computer (and I’ve confirmed the other bug’s behaviour was first introduced in the commits that added FMOD to the project) so I’m worried that there may be some nasty hard to track down memory corruption going on somewhere?
Think I might go a full wipe of the project and UE4 on that PC and set it all up again from scratch to see if something esoteric has snuck in somehow… Otherwise I’m a bit lost again!