Hi.
This does not sound like an issue specific to this mission.
I'm not sure what your problem is?
Is the overlay you are talking about showing all the time? if not then don't worry, all its telling you is PHYSX is running on the CPU, which is indeed true for Arma 3, even if you have an Nvidia GFX.
If it is on all the time you may want to consider looking around forums for posts concerning the same kind of brand PC you have, be it a laptop or not, to see if other people have this problem.
This sounds like a thing some companies will do, have a 3rd party app controlling a lot of your settings on your PC.