If you get "Origin is not running" error when you try to open The Sims 4: Deluxe Edition and ALL DLCs/Add-ons, follow these steps in order to fix it:
1) Check if you have RldOrigin.dll and RldOrigin_x64.dll in Game\Bin folder. These are crack files and they may false positive deleted by your antivirus.
1a) NO FILES! Bingo! Say hello to your antivirus, then go to it's stupid quarantine and restore them. If your AV doesn't even have quarantine (the stupidiest of the stupid) - completely disable antivirus and reinstall the game.
And don't tell me, that you don't have AV and those DLLs as well. Every modern Windows is shipped with Windows Defender antivirus, which is turned ON by default.
1b) These DLLs are in place. OK, go to square 2.
2) DISABLE your firewall completely or add TS4.exe & TS4_x64.exe to white list, ALLOWING these two EXEs Internet access.
Didn't help? Square three then.
3) Run the game as admin. Most probably it won't help, but who knows what rights you're using...