IF YOU ARE HAVING ISSUES CONNECTING WITH PEOPLE IN MULTIPLAYER and with resource desynchronization please, the issue seems to be with how GOH reads Steam mods. To fix this issue and make the game much more stable in multiplayer, follow these steps:

1) Navigate to your Steam workshop folder, the default is C:\Steam\steamapps\workshop\content\
2) Find and open the folder for Gates of Hell - the folder called "400750"
3) Find the folder for Hotmod. It is "2985063985". COPY IT (select, right-click and choose "Copy", or select and press ctrl-c on your keyboard).
4) Navigate to your Gates of Hell install folder. By default this is: C:\Steam\steamapps\common\Call to Arms - Gates of Hell\
4b) If you do not see a mods folder in your Gates of Hell install folder, create one (right-click, New > Folder and rename it to mods)
5) PASTE the SDG mod folder (2985063985) into this new mods folder.
6) RENAME this new pasted folder and call it "SDG" (without quotation marks)
7) Launch Gates of Hell and activate the local version of the mod. It will be called the same, but won't have info like size and last updated date.