You need to assign an actor to your user before you can do this

[arcanjl]

This is happening when any of my players try to take an item - what am I doing wrong?

[DanielBoettner]

Please check the things mentioned in the linked comment (an following):

https://github.com/jopeek/fvtt-loot-sheet-npc-5e/issues/303#issuecomment-1047525243