I was stacking controllers because it was the block I had in hand for getting scale, and this happened:
crash-2018-07-16_19.23.08-client.txt

Forge 2705, TIS-3D-MC1.12-1.3.1.17, ImmersiveRailroading-1.2.1_1.12, trackAPI-1.1_1.12, no other mods present (but I don't think anything but TIS-3D matters here, nothing else was in view)

Ah, this could happen when controllers in an errored state were in view and the player then was looking at a regular entity (monster, animal, etc). Thanks for reporting this!

I was pretty sure in that case I was just pillaring with controllers. I don't think any other entities were in view at the time

Hm, the error basically was if the player is looking at something the block pos of that info object not being set. Which was 100% reproducible with entities. Should always be set when the looked-at thing is a block, which is what I'm checking for now.

Well, I'll take your word for it. I'm trying to limit how much of how minecraft works internally I have to learn. :) Will this also fix #80?

Good choice for staying sane :)

And nope, needs a separate fix, but same issue basically, true. Will be up in a moment.