The Modern Warfare 3 Trello Board was a public tool used by the developer, Sledgehammer Games, to track bugs and fixes for the game. It was not created by Activision, but it was used by the developers to communicate with players about known issues, upcoming fixes, and other updates. The board was divided into three main sections: Known Issues, Fixed Issues, and Upcoming Fixes. Each section had cards that listed the specific issue, its status, and any other relevant information.
The MW3 Trello Board is no longer active, as the game is no longer being supported by the developers.
While the MW3 Trello Board is no longer active, there are other ways to get help with MW3. You can search for solutions online, or you can contact Activision support.