I've been trying to load my massive modpack, and I keep getting errors with lamp-post. Fixing it came down to disabling this mod in particular. The error is that lamp-post and small-lamp have mismatched collision boxes, which was fixed in lamp-post, but somehow unfixed? here.

Edit: Nevermind, on a super clean "this mod and nothing else", it loads fine. Wherever the problem is, the mod resolution solver can't find it. I'll report back in a bit once I've found it.

Looks like a heisenbug. Every time I come across it, disabling the offending mod doesn't fix it, but enabling that mod and it in a vacuum fixes it.