I ran into this same issue, after running the game successfully 3-4 times.
I had this problem 3 times.
At this point, possibly unrelated(?), the game won’t launch.
I am on Win 7 RC7100, x86
After buying the game it ran flawlessly, no need to run as admin, but I ran on an admin account after issues to test (both issues).
I did try going to the directory directly to launch as admin, with no luck.
Uninstalled and installed, same issue. Did it again the next day, same problem that will not launch. I get this error:
Purchased on Steam, running in their client. Other games are running fine.
I have not installed the update since the game ran fine before. Whatever version Steam has is what I’m running this on. Steam is up to date, drivers up to date, rebooted, open on firewall in case of validation issues, nothing blocking the game. Run as admin with no luck.
I’ll post this and another issue there when they activate my forum account.
Maybe a Steam problem on that second issue? Did the original poster purchase on steam or other means?
Edit: When launching the game, steam pops up my product key. I have not seen a place to input that, could that be the issue?