JCInventory, Grid based jigsaw Inventory for your projects

Hi, i bought JCInventory a few hours ago and i have followed your tutorial on how to add the inventory to a custom pawn.
I ran into a problem when i add an item to the inventory by class. I can see the item in the inventory but i cannot move it, drop it, use it or equip it. However i can place it into a hotbar. Any idea what the problem might be?