Here is the problem: I experience a crash which I can reproduce pretty reliably. Whenever I approach my TechReborn Blast Furnace multi-block structure, my client crashes with the following error:
https://pastebin.com/K7QctDbh

I wasn't sure whether or not to post this on the RC or TR GitHub, but as the multiblock is from this mod, I went with it. This has been going on for a couple of versions.

Not reproducible in 1.12