Your server failed to load the mod, thus losing all resources from this. This can happen in two ways, either corrupt or bad mod files, or server manager bugged.
You can still rollback to an earlier autosave once u fix the load problem, that would restore your items. See my troubleshooting post how

This is every modder's answer: Rollback... :P I lost stuff from different mods so many times that I don't care anymore. Glad, that I'm an admin and can calm down the players on my server^^ But isn't there a way, that resources don't vanish? I don't believe it anymore, that the server failed to load the mods - come on, 7 times now (not only your mod - this was just the 1st time with stacks and another loss was the egg n poop collector). But I have to say that I really love your stuff - they make life in Ark so much easier! :)

Well I believe that it's due to server managers. I hosted a server for a year running 30 mods including mine, never once did I get any problems using official steamcmd without ui server managers. But when I once tried a downloaded ASM, it caused many mods not to load properly whenever they updated, so that's something i know.