I'm having some issues using EnderIO on my custom 1.7.10 modpack server. On singleplayer the mod works with no issues, but me and some friends are running a server and the mod simply doesn't work. The mods used are identical between the single and multiplayer versions. When attempting to craft an EnderIO item, it appears in the crafting result, but the item number is "-1", and the items do not appear in NEI. The server sees the mod .jar as a "non-mod file" when loading.