everything modded keeps disappearing

[GayGnome]

So, I've been trying to play some modded terraria, but for some reason most of the time when I open tmodloader, it says that it's going to update.
When this happens, it acts like I just installed it, asking for the language and stuff and then it loads the mods, but every modded thing, npcs, items in chests, blocks, biomes, just disappears from every map. The characters stay untouched but everything else is gone.
help pls

[chummychum4]

me to