Small issue when reassembling, some sub-components get Equipped before you insert them into a parent, and the Sub-component is left 'equipped' despite no longer existing as a discrete item. Can cause script errors when the player or something else tries to un-equip the phantom item.
Can be worked around by equipping something over it to replace the phantom.
After ISInstallFireamPart is finished, the installed part is still equipped in the hand even though the item was removed from the inventory.
Originally reported on Steam by user Psieonic: