Error message: missing game data, install legacy edition. Please help

@Zkirky86  Try repairing the game in Origin: open your game library, right-click on the Sims 4 icon, and select Repair.  Then switch back to the 64-bit version: right-click on the Sims 4 icon, select Game Properties > Advanced Launch Options, and choose 64-bit from the dropdown menu.

If you can't switch to 64-bit, it's possible your antivirus is blocking or even deleting TS4_x64.exe, which runs the 64-bit version of the game.  Try disabling your antivirus temporarily and repairing again.  If it works, you can set exceptions for TS4_x64.exe and Origin.exe.

@puzzlezaddict i did the repair, it seems every time i try to play now i have to repair, any ideas on what the issue may be? had the pc and the same antivirus for over a year along with the games. i didn't see an option to set exceptions for TS4

@Zkirky86

Antiviruses are updated from time to time and after the latest updates, most of them suddenly started blocking the game files.
This applies to antiviruses such as Avast, AVG, Sophos, MacAfee, and even Kaspersky. I've seen a lot of identical cases recently and the antivirus program was always to blame
Just try to disable it temporarily for the test. Google its name, plus the word Disable. Then search the links provided for instructions on how to do this.
After disabling the antivirus, repair the game in Origin to fix the blocked files.
Origin./My game library - right-click on the game cover - option: Repair

P.S. But you don't really need this program, because practically Windows Defender on Win10 protects your computer sufficiently. This belief that you need to have an additional program comes from the times when Microsoft's security was not sufficient.

I don't work for EA

@Zkirky86  Your antivirus may have added a feature or become more strict at what it blocks.  It's also possible that Sims 4 recently added a feature that was always blocked; that's what seems to have happened in November.

What antivirus program do you use?  There are several for which people have posted screenshots of the necessary settings.  Or you could check the support page for the program.  And you're looking to add TS4_x64.exe as an exception, but you can only do this if it's currently installed, as in, you've done a repair and put it back.