# don't do anything else
# spawn ship core
# do a /force_save (to be sure)
# hold right click in astronaut mode while aiming at the ship core
won't be able to pick up the ship core
# now place down a block on it
# spawn in a new ship core
# try to remove that one now
should work
# now place down a 'block' when you have an empty slot selected (do it in build mode)
# try to remove a ship core again
won't be able to pick up the ship core