Feature Gen Crash

[GamerGaven]

Link to crash report - https://paste.ee/p/HvRwI
Was flying around in a world to test mods then received a crash after some time flying about, attempting to load the world back up causes the world to deadlock.
Tested it twice within same seed and same location producing same result.

[Patrigan]

Looks like the caves and cliffs backport is doing something not nice with my structure processor. Unsure what they're trying to do.