This has been occurring since the snapshot 18w7a and so on...
I entered in my map normally to see where certain new biomes would be spawned, but I approached a new Chunk my map crashed.
North, South, all paths with new Chunks generated crashing my map and when trying to enter again I was Disconnected.
Incredibly I've been with this map since 1.4 and in 1.7 nothing happened, I hope it's a Bug and if it's possible to fix it!

thank you! C: