So this is kind of a glaring issue to me, but I guess it's something that could be avoided.
Roll20 is aware that 3D dice rolling isn't supported in my browser (Safari). However, when I try to do a 3D roll, rather than error and cancel that instruction gracefully, it simply crashes Safari's web layer (causing every window and tab open to re-open, effectively refreshing).
Now I know I should never try to do a 3D roll again, but not error-handling that is a huge liability to any new users, as well as those who don't quite get that they can't do that. I would highly recommend just checking the browser (which you clearly already do elsewhere in the app) and then just give a simple "this feature is not supported in your browser" sort of error.