There is a conflict between BOP and BuildCraft which causes Minecraft to crash when creating a world https://pastebin.com/3kiPeg42

Oh it seems this issue has been reported already, sorry for having reported it again, I close this one.

does this heapen every time when generating a new world? if so then it is not the same as #3640
if it is heapening every time you want to report it to BOP as then they are parsing an invalid biome ID to generate terrain

Yes it happens at each generation with Biomes O' Plenty 6.1.0.2239 and upper versions.

yes this is an issue in BOP itself, BC is crashing because they are triggering worldgen with a biome ID that doesn't exist