[CURRENT ISSUE] Sims 4 Unable to Start, Game Data Missing or Damaged

@Destroyer1941  Can you repair the game now?  If not, I would recommend uninstalling it and the EA App with Revo Uninstaller.  For Sims 4:

• Put aside your Sims 4 folder in Documents\Electronic Arts and rename it to something that doesn't include the words "Sims 4."
• Download Revo Uninstaller (the free version is fine) from here.
• Launch Revo, select Sims 4 from the list, and click Uninstall.
• Cancel the system restore point; you don't need it.
• Once the game is uninstalled, select "Moderate" under "scanning modes," and click Scan.
• Review the list, in case there's something you want to save; otherwise, click Select All, and then Delete.
• Close Revo, and restart your computer.

For the EA App:

• Launch Revo, select the App, and click Uninstall.
• Cancel the system restore point.
• The EA App may open a window.  Click Uninstall, then in the Revo window, click Moderate under Scanning modes, and click Scan.
• Revo will present a list of registry entries.  Click Select All, then Delete: you don't need or want to preserve these entries.
• For the leftover files and folders, click Select All, review the list and deselect anything you'd like to keep (this is unlikely, but it's worth checking), click Delete, and you're done.
• Close Revo, and restart your computer.

Install the EA App, then create a new folder into which you'll install Sims 4.  The folder should be on the root level of the drive of your choice, for example C:\Games is fine, but not C:\Program Files\Games.

If the repair worked, but you still can't play, please create a new admin Windows account.  Make it local, as in, don't link it with your Microsoft account.  You'll be able to (try to) launch Sims 4 without reinstalling anything.  Let me know how it goes.