100MB worlds cannot be copied

I wanted to copy my world so I can use experimental gameplay and the world is 204.7MB. The world will be recorded in a Minecraft role play series but that isn't going to happen if I can't enable Experimental Gameplay. And now Minecraft says 'Failed To Copy Icewood(Pierland)' right after 40% copied. This failure needs to be fixed for all players who need their world that are over 100MB to be backed up. If mumbo jumbo can have his 3 year old Redstone workcal backed up, then why not ours.