After upgrading this Minecraft world from 1.21.11 to 26.1 it completely corrupted all the border regions ("region" being a set of 32×32 chunks, with a chunk being 16×16 blocks), very weird. All previously-generated chunks and new regions are fine, but any partially-filled region (at the borders of the area I had explored in 1.21.11) that I moved into had all the ungenerated chunks filled completely with air, so there were just massive voids around the entire area I'd previously explored. Could only get it fixed by going in and deleting all the empty chunks and then they all regenerated fine
@nytpu this is cool to see the underground cross-section

@nytpu

That's kinda neat, though.

Inconvenient, sure, but also very atmospheric.

@nytpu
Reminds me of the farlands a little.
@nytpu this would've been so cool though. you could build some cool bridges over the void there
@dzwdz I saved a copy of the corrupted world but eh, I dunno which version I'd prefer playing; there was just so much corruption. If it was a little bit of corruption then it could've been a cool moat around an island or something, but like 10,000 square chunks surrounded by a 2–20 chunk wide void on all sides is a lot

@nytpu
not gonna lie, this looks very cool for building things in creative.

probably a pain for survival.