Startup 'Unable to start' error.

A couple of days ago, my game was working fine besides the fact that none of my mods were in the game. The next day I tried going on The Sims 4, the Origin message came up. 

[Cannot start because required game data is missing or damaged. Please repair or reinstall the game via Origin.]

I've looked through other topics and tried blocking and allowing certain files on my firewall and reinstalling the game folder but it does not work. I don't use ZLOrigin. This has happened before but I'm not sure how I resolved it last time. Thanks for any help.

shayleon wrote:A couple of days ago, my game was working fine besides the fact that none of my mods were in the game. The next day I tried going on The Sims 4, the Origin message came up. 

[Cannot start because required game data is missing or damaged. Please repair or reinstall the game via Origin.]

I've looked through other topics and tried blocking and allowing certain files on my firewall and reinstalling the game folder but it does not work. I don't use ZLOrigin. This has happened before but I'm not sure how I resolved it last time. Thanks for any help.

Hello again,

Files and folders don't "corrupt on their own". If they do, it could be an early sign of a failing hard-drive, which in turn I suggest you try and replace as soon as possible. If you want to try and fix your game, use anadius's validator first and then copy-paste the validator results in a reply here:
https://anadius.github.io/sims-4-tools/validator.html

Then again, if you are at a stage at which the files become corrupted, you might instead want to focus on getting some new hardware. May I also ask if you are playing on a laptop computer? If so, these hard-drives are even more prone to failure than your traditional desktop computer drives.