Savannah error code can be pretty annoying sight in Call of Duty: Modern Warfare but fortunately, there's an easy fix that should allow you to play the game as intended.
Call of Duty: Modern Warfare is a great game and probably one of the best in the series in the last couple of years but this doesn't mean it's completely flawless. No game is to be fair and this is especially true for big online multiplayer games.
Of one the most common problems you may have encountered in Modern Warfare is a simple error code message that says "SAVANNAH". This usually happens once players try to connect to a friend's online session. The full error code often reads: "Unable to join game session, the host cannot be joined or gameplay is paused. Status: SAVANNAH".
Luckily the fix for this issue is pretty easy. There are a couple of things you need to do but you can start with checking your game version. Make sure that you are running the latest version of Modern Warfare and that all updates have been downloaded and installed.
If you don't have the latest update installed, the game won't allow you to join your friends' party or enter lobbies which will result in SAVANNAH error code.
If this doesn't work for you, we have another fix that might be helpful. Thanks to a Reddit user callzn, you should try deleting the files in the screenshot below. Go to Call of Duty: Modern Warfare install folder and enter "main" folder. There you should find the files from the screenshot. Simply delete them and go to Call of Duty: Modern Warfare options in Battle.net and scan and repair the game.
If you’re on Xbox try uninstalling the reserved data and then when you load back into the game it should update again, which will hopefully fix the issue. PlayStation 4 users need to find the game's icon and select Check for Updates in the options.