Post the crash log here.

I've taken a lot of time testing this to make sure that chest placement aborts if it thinks you're about to lose a chest/items, but something might slip through the cracks.
If a chest disappears after being placed down, write a post below with the following:

1. The X and Y of the location that you picked up the chest from. This can be found by pressing F2.
   
2. The backup files located at "%appdata%/Necesse/cfg/mods/moveit"
   
3. Your character save file, found at "%appdata%/Necesse/saves/characters"

If you provide those three things, I can attempt to recreate the chest, or at the very least try to restore the items.