I've tried with the latest Default (7.1.8) and latest Altasaurus (7.1.9) and I have been seeing the same crashing behaviour, though BugSplat never appears. Usually happens if I land on a region and other avatars are still not loaded. As they load, sometimes a network glitch happens and the viewer crashes. This also happens if I'm in a dance club. Other avatars may (finally) load and render, but as people change their dance animations, I would crash unceremoniously. I never crash if I'm on my own on a sandbox place. This behaviour seems to be like this for the past 3 or 4 versions; it seems when some transfers fail (due to glitchy internet) the viewer crashes instead of falling back to something safe.