This was reported here Caltinor/Project-MMO-2.0#707 regarding PMMO. I am unsure of the specific circumstances which cause the relic on the spore entity to be empty, but that appears to be the cause of the downstream crash. I expect a "not empty" conditional around this line would be sufficient to prevent future crashes. The read method seems to already capture the absence of the stack with an optional check, which i believe would make this solution suitable.