Re: Sims4 Game already running

@TCProduction  If OneDrive is running on your computer, whether you use it or not, try pausing syncing before launching the game.  The option shows up when you right-click the cloud icon in the lower-right corner of the screen.

If that's not the issue, please set exceptions in your antivirus for TS4_x64.exe and EADesktop.exe.  If you only use Windows Defender, find out whether Controlled Folder Access is enabled.  I'm not suggesting you turn it on if it's not already running, but if it is, set those same exceptions.  Here's how:

https://crinrict.com/blog/2019/03/windows-10-defender-controlled-folder-access.html