Non-valid entities in pirate stash

I'm not sure how this happens entirely, but sometimes pirate stashes can contain entities that return false on inst:IsValid(). This causes a crash when the stash is dug up due to inst.Transform:SetPosition()

Below is an example of what a friend of mine got when printing the contents of a stash (and whether they're valid or not) before digging it:

[01:26:46]: 1    122693 - goldnugget(LIMBO)    true    
[01:26:46]: 2    122695 - goldnugget(LIMBO)    true    
[01:26:46]: 3    122697 - bananajuice(LIMBO)    true    
[01:26:46]: 4    122699 - bananajuice(LIMBO)    true    
[01:26:46]: 5    122701 - blueprint(LIMBO)    true    
[01:26:46]: 6    121811 - monkey_smallhat(LIMBO)    false    
[01:26:46]: 7    121801 - monkey_smallhat(LIMBO)    false    
[01:26:46]: 8    121806 - monkey_smallhat(LIMBO)    false    
[01:26:46]: 9    121814 - cutless(LIMBO)    false    
[01:26:46]: 10    121809 - cutless(LIMBO)    false    
[01:26:46]: 11    121799 - cutless(LIMBO)    false    
[01:26:46]: 12    121804 - cutless(LIMBO)    false    
[01:26:46]: 13    121816 - monkey_smallhat(LIMBO)    false    

Fortunately (or not), the invalid items get removed when the save file is loaded. This does make the nature of this bug difficult to test, however.