Re: core/activation64.dll missing

@noxvortexx  It may not be related, but the XBox Gaming Overlay is throwing errors, so start by disabling Game Mode and Game Bar.  Both settings are found under Windows Settings > Gaming.

For the error itself, can you use your phone as a mobile hotspot?  (Make sure it's using data, not your home wifi.)  The point would be to try to launch the game with the hotspot connection, in case the error is network-based rather than something else.  I believe the Activation64.dll is involved in validating your computer's ownership of Sims 4, meaning connecting to EA servers.

If this doesn't help, do you own any other EA/Origin games that include an Activation64.dll as part of the program files?  If you're not sure, try searching your computer for the file.

@puzzlezaddictYes, I own The Sims 3, but I had to uninstall it due to lack of space. I had it on Steam, and this issue seemed to have appeared after uninstalling The Sims 3. I will try it with my phone as a internet hotspot but it’s usually worked just fine with our home wi-fi.

EDIT: I did some searching on the Internet, and apparently the Activation64.dll is a DRM file by EA, which is apparently supposed to protect copyright. I don't understand why my PC is reporting it as missing/not working, as my copy of The Sims 4 is legitimate. I really need help with this. Should I just uninstall both The Sims 4 and Origin, clean the registry from any traces of them (I would also like some help with that) and then reinstall both? I'm so confused... I've tried everything!

EDIT 2: I tried the phone hotspot but it also didn’t work. I also have an old install of The Sims 4 on my old disk drive, but that didn’t seem to cause any problems before. Should I try reinstalling The Sims 3 though?

Okay so for me the error went away by first uninstalling Origin the hard way and then reinstalling it and repairing the base game!