Okay so i recently used the prune option on mcedit to delete my entire world exept for my giant base because i was getting nothing but ice and snow biomes. it worked..... exept that when i explore my level the game seems to generate the same land that was there before i started impacting on it eg burnt forest = normal forest. could someone please tell me how to use the prune option without this happening? i apologise if posts about map editors are against the rules.