Once you've downloaded the file, follow these steps to install it:
Instead of downloading the file from a shady third-party source, you can force your official game launcher to acquire a clean, legitimate copy of the file. Method 1: Verify Integrity of Game Files (Steam)
Reopen Battle.net, click on Call of Duty, select the next to the Play button, and click Scan and Repair .
If you encounter any issues during the download or installation process, here are some common problems and solutions:
If you are playing Modern Warfare or Warzone on Battle.net, corrupted cache indices often trick the launcher into thinking a broken file is completely fine. Clearing these out forces a clean redownload: Close the game and the launcher completely.