Have searched all over for a definitive solution to this problem to no avail so hoping someone here can nail it.
Installed the latest version kindly linked by _Antithesis_ plus the patch included. Completed the 3rd(?) mission, the sniper one and then watched the cutscene after which screen went black and received the "Origin not installed..." error message. Tried replacing the MOHW.exe with the "Update v322991 Fixed Files" from Battery but same thing happening.
It was installed offline but thinking that maybe I didn't completely block the game in my firewall and when I went back online it somehow connected and f*cked me up. Game is now uninstalled.
If anyone has a proper fix for this I'd really love to hear from you! Thanks