Basically the title. This doesn't affect any cave biomes. To recreate this you just have to enter "REDApRES" into the seed field and create a new world. After that you can locate and tp/walk to any of the new mountain biomes except Meadow and the world will crash. I tried this on a server and the error was "java.lang.NullPointerException: Cannot invoke "dfw.a(double, double, double)" because "this.a" is null" and the server closed with error code "255".
I understand that technically seed "0" isn't even supposed to be entered but it have worked with all previous versions so I think this crash counts as a bug.
My guess is that this new mountain generation is completely based on the raw seed so there probably won't be any fix for this bug but I am still reporting it because I often use it and I got hope.
Description: Exception generating new chunk
java.lang.NullPointerException: Cannot invoke "dfw.a(double, double, double)" because "this.a" is null