Board Thread:General Mod Discussion/@comment-2601:147:C080:20AF:FC2F:BE75:2516:A61D-20181202015208/@comment-31507215-20181202072507

I don't have much knowledge on this, but I have seen similar comments before. I think that the swapped blocks have something to do with a hiccup related to block IDs. That's all I've got, but MilkMC can probably do more for you.

Do you have any other mods installed?

Also, for the future, the Bug Report board is a good place to post questions and problems like this.