Was flying around in creative in a new world and all of a sudden the game froze then crashed
crash-2019-09-22_21.48.57-server.txt

As per #494 this seems like it isn't fixed.

same crash here in version 0.25.2.86 crash-2019-10-21_19.42.08-server.txt

Just got this again with build 87 along with Worley's and several other mods.

I believe that this is to do with lava + water forming basalt cobblestone, which then quickly becomes a falling block, causing an infinite loop of forming more cobblestone and creating falling blocks. The resolution is to switch the formation of basalt cobblestone for rhyolite raw stone. (although what would form vanilla stone still forms basalt raw stone)

got the same crash: https://paste.dimdev.org/qiwubecija.mccrash

Got the exact same crash just now in my main world
crash-2019-09-28_10.58.16-server.txt

same here https://gist.github.com/trilexcom/ccc45f32275cdc959861adf98bfcf1f7