missing chunks / hole in ground

[vonjoe98]

Hi everybody

Yesterday I was playing mc/voltz when suddenly a massive hole appeared. I'm sure that it is a chunk failure, cause its 16x16 blocks and has no end and I can fall down just a few blocks then it stops. Also interesting is that the game is much slower than before and that the rain in the chunk is black and it should be snow not rain. I already tried to restart voltz a lot of times, also to delete it and "install" it again, but there's no difference.

Has anybody an idea? Thanks a lot for your help