Caused by new update, not sure if it's incompatibility or a networking error. My money is on networking, since the modpack functions fine in single-player.
Adds 50 new items! · By
From what I can tell, it *is* mod incompatibility, since I've played a few games with my friends since the update, and it all works fine on our modpack. Will try to figure this out at some point. For now, I recommend just rolling back to a more stable version of the mod (like 2.1.2, for example) and seeing if that works