Edited with solution:
I had disabled my antivirus software, but turns out that Windows Defender was recognising it as a virus. Just click on "Restore", and add the file to "Allowed" list and it runs as per normal. Can't test the achievement getting aspect though as I have all the achievements so far
[Edited by yayyap159, 5/6/2020 11:47:40 PM]
I can confirm that this works. I didn't even think about it being a Windows Defender issue since the message that popped up was from Steam and not from Windows Defender. I find it odd that Windows Defender didn't provide any notification regarding this, but a Steam error message is what ended up popping up. Either way, thanks for the tip!
Anyone know when the trainer for Halo 2 Anniversary in Halo: MC gonna come out?
Can't wait to play this game! 😁
They should release an Halo 2 version soon. I believe Halo 1 trainer came out a day or two after it was released. Give them time