Do you use a dedicated server in the dev kit? I have a feature in my mod that hides engrams, so it’s kind of like what you’re doing (modifying an array based on certain conditions). I’m not ready to push it to my dedicated server for testing, but it works in the dev kit’s dedicated server mode, which crashes me for not being the host sometimes. I’m using Event InventoryAccessed, and it works fine. You should try using Event BPNotify ItemAdded, and see if you have any luck there.