Same thing happened to me. Reputation halfway to S, when signing up for the scientific mission with the tornado. Finished the mission with an S rating, but upon finishing the score first says infinite xp, then NAN, then arond 250.000xp + no skip etc. Upon returning to HQ the game crashes to desktop.
When loding back in reputation drops to C (one third on the way to a B)…Pretty pi$$ed right now. All those missions and rep for nothing…If this is not fixed and reputation restored, I guess I’ve had it with the entire career mode.