So no meaningful resolution to this problem, but mojang is now redirecting new reports of this error to other "resolved" threads that don't actually work. Well, looks like I'll be stuck playing 1.12 for the next four or five years as I can't replace a computer for just this game. Awesome.
Laura M. I believe the comment by Peter is fair, given that he is responding to the fix offered up by the moderator note.
Has anyone else who is also having this problem found a fix that works?
I recently updated to High-Sierra and there was also a new java update that has since fixed the issue for me personally. If you haven't tried that, I'd see how it goes.