Why is there a conflict on my server but not SMP?

Hi, my friend and I recently made a modpack for Minecraft and I'm running the server on my PC and we can both play the mods fine in Singleplayer, but when we go to the server, all of the mods are present, but none of the items from any of the mods are working. When we try to craft the items, the block shows in the output of the crafting table when we put the recipe in, but when we try and click the item, it doesn't let us. We aslo couldn't open up Baubles Inventory or the Tinkers' Construct Inventory. Mods we're using: Treecapitator, Ars Magica 2, Applied Energistics 2, Biomes o Plenty, Blood Magic, Botania, Buildcraft, Ender IO, Extra Utilities, JurassiCraft, LLibrary, Mantle, NEI, Thaumcraft, Witchery, Animation API, CodeChickenCore, bspkrs Core, Baubles, and Code ChickenLib. We're using 1.7.10 for all of the mods.