I'll click "play" on steam, and it won't launch. It'll say "running", then immediately say "syncing" and close outright. I can run the Arma.exe itself from the folder, but the launcher won't run, nor will it run in administrator mode. Looking at Task Manager, the launcher runs in background but instantly says "suspended" then closes. I've reinstalled .NET which hasn't fixed it, I've verified the game files but that hasn't worked, I've gone into AppData and deleted the file beginning with arma3launcher.exe_URL but that hasn't fixed it, running the launcher in safe mode didn't work, nor has a clean reinstall of Arma itself helped.

I did find this thread which had the same issue I have. https://feedback.bistudio.com/T82849

However, the fix doesn't seem to be up anymore and I'm unsure whether it applies to me anyway.