In T127189#1660701, @aerophyle wrote:

I wanted to post a solution here that is working for me, though I don't know how much it will help others. I bought Squad recently and it was working, but it forced windowed mode and when I set the graphics to full screen the game was getting the same failure to start error. I took this as a clue and, under compatibility settings for the game, I checked the DPI scaling and full screen optimization boxes. For some reason, this got the game working for me. They do not open from Steam correctly, but I can finally play again. I hope this helps some of you guys, since it ties in with the forced windowed mode "fix."

Okay, so i have contacted Nvidia Support. They have referred me to what was apparantly a Windows issue. They let me set the 'Force WARP' option in DirectX. This solved the issue with Geforce Experience only giving a black screen, but ArmA III still gave the same error. I was then advised to roll back to Windows build 1703. Which i did.

@Wulf I was hoping AnEnglishmanShels' solution would also solve the problem for me. I've completely reformatted and reinstalled my computer today. I've just finished completely updating and installing everything. however, I'm afraid this has not yet solved the problem, i'm seeing the exact same error every time i try to start the game. Both in x64 and in x86 versions... I'm at a loss here really.

Sadly i've now also ran into this issue. ArmA ran very well up to now. I hadn't played in three days and apparently something happened in that timeframe that has resulted in ArmA no longer working. The Launcher works fine. The ArmA III loading screen with the loading bar becomes visible after pressing 'Play' and after the loading is complete, it dissapears. After a few moments a prompt appears stating a error has ocurred. I have attached a screenshot of said error-prompt.