Forge Server asset loading errors

My brother and I have a modded world we've been playing over LAN for about a month now - I'm going to be out of town for two weeks and am attempting to set up a forge server for us to play it on during that interim. We're running Quark, Biomes o' Plenty, Vertical Slabs, the Dalek Mod, and a few others... I can run the server just fine, and all the mods work, but when I tried to move the world to it and launch, it threw a lot of errors on not being able to find recipes, structures, and other assets. It launched anyway. When I connected, however, all of the modded blocks were gone. It seems to have still loaded the mods - I attempted to /give myself a modded item and got as far as the autofill showing the mod option before my connection "timed out". I think that last may be because we're having internet issues today, though, and will confirm/deny tomorrow. For now I'd like to know if I did something wrong moving a client world to a server?