Double check the contents of the res_mods folder especially the naming conventions.
WG sometimes micro-patch and change the folder names. When that starts to occur, there can be inconsistencies between the game client and the mod pack.
For example on the SEA server, we are sometimes last to get a patch and the mod packs we use that get updated for NA/RU/EU will not work on SEA until the server is patched.
(Might help identify your issue)