If your game won't start after you have installed content with the TSR CC Manager, it could be because you have a file installed more than once (once in the CC manager, and also a version loose in your MODS folder).  

Another cause can be a file that didn't quite download properly and completely, or perhaps was interrupted by Onedrive backing up the file before the CC Manager could install it correctly.  Whatever the cause, a non-working game is NOT fun!

Before you begin - tips to simplify troubleshooting

Note: This section with talk about the TSRLibrary folder.  This can be found in Documents/Electronic Arts/The Sims 4/Mods/TSRLibrary 

When you have a couple of hundred downloads, the above is a workable solution, but what if you have THOUSANDS?! 

• If your game doesn't start because of a recent download, you can move all archives except the newest-dated from your TSRLibrary folder to a safe place (you might need to change your folder's VIEW settings to "detail" in order to see the date each file was last modified).  Leaving only the latest archive in that folder will eliminate a lot of download testing!
  
  
• If you have an idea which archive(s) are causing the issue (either because of an entry in the REPORT A BUG log or through elimination, again, remove ALL others from the TSRLibrary folder to a safe place. 

Fixing your game

1. Try this first: clear your Mods folder

The Mods folder can be found in Documents/Electronic Arts/The Sims 4/Mods (or The Sims 3).  Back up a safe copy, then remove ALL package files and any folders not beginning with the letters "TSR".  Also leave your resource.cfg installed.  Everything else should be removed.  Try your game.  If it now starts, you have a duplicate file loose in your Mods folder.  If it doesn't, there is a problem file in the CC Manager.

2. Troubleshoot downloads in the TSR CC Manager

If clearing your Mods folder didn't help, do not replace the files (yet).  The next step will be to isolate the troublesome file(s) interfering with your game.  Note: you might want to take a quick look at Tips to simplify troubleshooting below first which might save you some time.

1. Important, ignore all red warnings!  Do NOT attempt a repair when following these steps.
   
   
2. Uninstall (don't just disable) ALL files in the CC Manager until nothing left is installed.  All your downloads will simply move from the LIBRARY to the DOWNLOADS tab and they will no longer be in your game.
   
   
3. Go to the folder Documents/Electronic Arts/The Sims 4/Mods/TSRLibrary and delete any stray archive files in there.  Your game should now start.
   
   
4. Go to the DOWNLOADS tab of the CC Manager and install just one item (preferably something simple like an item of furniture or a piece of clothing - something that won't have other dependencies like many lots, rooms and Sims do.
   
   
5. Test your game
   
   
6. Continue installing just a few items at a time, remembering what you're installing in each batch.  Keep going until your game won't start.
   
   
7. The faulting file will be in the last batch of files you installed.  Uninstall that last batch, then try the files one at a time until your game stops working again.
   
   
8. When you have located the file, you can link to its download page on our website from within the CC Manager.  See whether it has any required items you are missing,  If not, try downloading it again to see if that fixes the problem.  If it does not, please report the creation on the web page and our submissions team will investigate.