hi guys,
I have had the same problem but just without carpenters blocks.
I was playing a world with my friend and we were exploring new chunks, i was in a archimedes ship and he was morphed as a ghast.
when we left the world, the next time we joined again and again he would join, open to lan and then when i joined the whole thing would crash again.
please help he is really angry at me for ruining his world thanks FERNOVEN