In dnd5e 5.3.0, when I import an Explorer's Pack from the SRD and then try to use "Display in Chat", I get this error:

item.mjs:731 Uncaught (in promise) TypeError: Cannot read properties of null (reading 'token')
    at Item5e.displayCard (item.mjs:731:27)
    at Object.callback (inventory.mjs:351:28)
    at #onClickItem (foundry.mjs:29216:12)
    at HTMLElement.<anonymous> (foundry.mjs:29167:62)

Specifically, this is what's happening: the context object creation is trying to pull a token from the actor associated with the item, but a sidebar container has no actor.