This same thing happened to me when I tried to copy shape and I think it ended up hitting a block that was a terrain block. My character has become completely unusable and I had to delete it from the server to be able to log back on again. So now I get to try to guess what all perk books I had to give them to myself again to get back to where I was . I think if I had a way to just delete the block from my inventory it would work fine but I don't know of a character editor that works in A18. Edit: I was using the flagstone helper block at the time.