[1.7.10] New worlds stuck at "Converting World" (Mo Creatures)

[DestinyPlayer]

Forge - 1614
When I try to create a new (in particular, a default superflat) world, the game stops at "Converting World". When I look into the log, it says "[18:04:37] [Server thread/WARN]: Unable to find spawn biome" at the very last line. When I removed Custom Pets from the pack, the problem ceased.
The modlist - http://prntscr.com/c6gd7k
The full log - http://pastebin.com/fZX5VJ6F

[DestinyPlayer]

Additionally, it also crashes when I add Mo' Creatures back. I have no idea what's the problem though, and if I only have Custom Pets, without Mo' Creatures, it still crashes.

[DestinyPlayer]

Okay, I think that when I install Mo' Creatures, it breaks Custom Pets until I uninstall them and reinstall them back again. Sorry for notifying, but I'll leave this here, just so you know.

[capnkirok]

Cheers. I can take a look. Thanks for the report. Will leave it here as well until I can investigate.