I have the exact same problem on my laptop (High Sierra 10.13.4) and haven't been able to narrow it down. Margin only runs for about 24-72 hours before it "quits unexpectedly." At first I thought it was triggered by having too many exchanges and pairs (running Binance and Bittrex), but even after reducing the footprint to just Binance, with less than the max recommended pairs, and bare charts without any added indicators, the problem persists.
I'm considering either setting up a Linux VM or running it on my Windows PC to see if it's OS related, if I find the patience.
There's a tradeoff between the two applications. What I've noticed is that Margin is relatively light on memory usage, but destabilizes within a couple days. Leonardo eats a huge amount of RAM/swap (possibly a slow leak) but is otherwise rock solid over literally several weeks. My last instance set a personal record at 52 days of uptime before I shut down to update the OS, though by then it showed >100GB memory usage in Activity Monitor and had to be force quit. This was again with Binance plus Bittrex and around the max number of recommended pairs.
New bots, drawing tools, and social media integration are useless to me if I have to babysit the application, and more complexity will just make it harder to narrow down stability issues. I can try to keep troubleshooting to see if there's a pattern with the crashes, but the team should be able to easily test this scenario. Use the latest versions of macOS and Margin, open Binance and Bittrex, add the max recommended number of pairs to each, and just monitor it for a few days. That would at least tell us if the error is reproducible on your end or if it's something specific to our setups.
Following up to say that v1.1.1 has resolved the near-daily segfaults that I was experiencing with earlier versions. My current uptime is 8 days, with 6 pairs on Bittrex and 30+ on Binance (way over the suggested limit but I haven't been IP blocked yet), and a small handful of active MM and BB bots.
Thanks!