Why do I get the EC-CMINV error when installing a game from the Epic Games Launcher?

When attempting to install a game from the Epic Games Launcher, you might receive an "EC-CMINV" error that prevents you from installing it.

Please try the following troubleshooting steps to resolve it:

1. Run the Epic Games Launcher as an administrator as per How do I run the Epic Games Launcher as an Administrator?
2. Make sure the secondary launcher of the game is installed and up to date (e.g. EA app, Ubisoft connect, Rockstar Games Launcher, etc)
   Note: If you're missing the secondary launcher, please download it from the developer's official website. 
3. Try installing the game again

If you are still receiving the error, please collect your Epic Games Launcher logs by following How do I gather logs for Epic Games Launcher? (make sure to replicate the error when generating your log files) and submit a support request.