Not sure if this is in the right section.
So I was having issues with CoD launching from battle.net. I tried some other fixes mentioned from research but nothing resolved the issue. Below are the steps I performed which resolved the issue.
I would recommend getting revouninstaller and uninstalling battle.net, after that has been completed reinstall battle.net. (You do not need to uninstall all games).
Once battle.net is installed you can install CoD a portion at a time. I installed just the base game (This does not include BO6, at least on mine it did not). After the install completes I tested CoD by launching and there were no issues.
Proceed with the same steps for each portion of CoD until all content you have purchased has been installed.
My install sections were performed in this order
1st base game
2nd modern warfare II
3rd warzone
4th modern warfare III
If you have other content just proceed with the installs the same way making sure to break them up into portions. Hopefully this helps.
GG, Happy Hunting
R3AP3R