I bought BO6 Vault edition and own MW2 and MW3 on Battle.net. Call of Duty says it needs to perform an update and sends this error right away. I have tried all the suggested solutions like reinstalling Battle.net, deleting cache files, etc. I opened a Blizzard support ticket they offered the same canned solutions that I have already tried and said if that doesn’t work check the forums, as the other users might have a solution. Okay. Sure thing. Ubetcha.
*Miracles do happen. For the hell of it, I did another scan and repair on the Call of Duty files from battle.net. Left for an hour or so and came back and the game button was set to play instead of update and it appears to be working. My guess is they fixed something on their end this morning.