Your Map Differs From the Servers Gmod Fix The most common cause of the "Your map differs from the server's" is that you have an outdated version of the map OR the server hasn't auto-updated to the latest version of a map and you already have. To properly fix the issue, you first need to remove the map from your GarrysMod folder, which can be found under your Steam folder in your SSD/HDD   Once you navigate here, click on the maps folder Scroll down to the .bsp