Update 8/11: It seems as though most of the Call of Duty: Modern Warfare and Warzone online connectivity issues have been resolved. Original story follows.
Infinity Ward recently released a new update for Call of Duty: Modern Warfare and Warzone that made a number of changes, such as nerfing the Bruen and FAL, as well as fixing an XP glitch exploit. However, ever since the new update, it seems Call of Duty: Modern Warfare players are having difficulty logging into both the standard multiplayer and the Warzone battle royale, with these problems being reported across all platforms.
The Call of Duty server issues appear to come in a couple of different forms. Some players are unable to connect at all, whereas others are finding themselves in "server queues" with the game telling them that it is busy fetching their online profile, with players unable to get beyond that screen. At the time of this writing, nearly 10,000 Call of Duty users have reported that the game is down to the Down Detector website, though Activision has yet to acknowledged the issue.
According to CharlieIntel, one potential fix for the Call of Duty: Modern Warfare and Warzone server issues is simply restarting the game. We were unable to test this method for ourselves at the time of this writing, but some users have agreed that it works. Others are still stuck on the "fetching online profile" screen, unfortunately.
Infinity Ward and Activision will likely fix this issue sooner rather than later, so Call of Duty fans should hopefully have a short wait until the servers are completely restored and they can jump back into Season 5. We will update this post once online multiplayer services have been completely restored.
Call of Duty: Modern Warfare is out now for PC, PS4, and Xbox One.
Source: Down Detector