Upon investigating #988, It appears that between MC 1.7 and 1.10 the interface net.minecraft.world.chunk.IChunkProvider has been gutted. Most importantly IChunkProvider#chunkExists was removed. The implementation class in vanilla Minecraft (net.minecraft.world.gen.ChunkProviderServer), however, still has this method and it can still be called by the server (by requesting the world's chunk provider).

RTG's implementation class rtg.world.gen.ChunkProviderRTG does not have a chunkExists method with this same signature ((int, int)) and I feel that there is the possibility that if a mod checks to see if a chunk exists by way of the world's chunk provider, it will result in a NoSuchMethodError.

Closing this for 1.8.9 as there's already a chunkExists(int, int)

I'm not sure why I added the 1.8.9 tag. The interface was changed in 1.9.4.