Hi Tommy,
I am also experiencing this issue. My hardware is completely different from the original poster.
CPU: FX-6100
GPU: R290X
RAM: 16gb
OS: W10
I would be cool with not being able to play 1.2 as long as I could play the other missions, are there any options to unlock further missions without playing 1.2? As it stands I paid for a game that I cannot use.