Minecraft v1.16.5
Forge v36.1.9
Vahelsia Structures v16.0.5
Bgcore v3.2
CCB v5.1

My server crashed while I was exploring. The crash occurred with Bgcore, which is the required mod for Caves and Cliffs Backport and crashed due to the biome height.
Crash Report

Just tested with the newest version of CaveBiomeAPI and it no longer crashes.

The issue is most likely caused on Bgcore's side so it would be good if you could also open an issue on their tracker.

Alright, thanks. I let the dev know in his discord and is looking into it.