One of my modpack's players submitted this issue a bit ago, and it seems to be a known issue with Oh the Biomes You'll Go and Quark.

Pastebin says I've exceeded the file size limit, so the log is on here on GitHub Gists.

You need to change the config to specify the BYG biomes

I didn't even know you could configure the spawn biomes lol (never knew this block existed).

Welp, sorry for the fake report then.