Might have something for you here @tehn
I’m getting fatal crashes twice in one week now, both in mlr. Not entirely sure it’s mlr-related, cause the repro (which isn’t 100% by any means, just the least common denominator when this has happened) is in the params menu.
Anyway, here’s what happens. I got a pretty heavy mlr session going. Four tracks, at least, both times this happened. Two or three patterns going and they’re pushing it - reversing, bouncing pitch up and down, stuff like that. Quant is turned on. Samples are fairly long, loops between 8 to 32 beats, resized and split up heavily.
So when I’m in the param menu, frantically scrolling (yes, frantically, I mention it because it might be related) up and down for whatever purpose - adjusting the pan on a sample, fixing a slew, whatever - I get a crash.
One of those crashes where K3 - K2 - K1 won’t help.
Mlr keeps on playing but the grid freezes exactly where it was at the time of freeze. Norns is unresponsive, nothing works. But the show goes on 
Also, both reverb and compressor is on. Reverb is subtle but the compressor is pretty active.
This has happened twice in one week now. Both in mlr, both when lots of stuff have been going on, both in the params menu as I’ve been browsing it for whatever reason.
I realise the repro isn’t solid and I got nothing from maiden (the norns is literally dead), but maybe it’s part of a puzzle as you’re working on updates.