Heya, sorry to post more of a query rather than an actual bug to your git, but I couldn't seem to find you on Discord or anything like that.

Please have a look at this issue I've posted to Deeper and Darker.
KyaniteMods/DeeperAndDarker#373

I wondered if the error might have something to do with a WorldGen incompatibility due to the error: [minecraft/UniformHeight]: Empty height range: [0 above bottom--8 absolute]

Have been scrolling through our modlist to look for something that makes sense in regards to this issue.

This wouldn't be a Tectonic issue.