Crash when scrolling on initial Markdown preview render (MacOS Sierra)

I noticed today that when I opened a rather large Markdown file in Macdown, and tried to scroll down immediately, before the preview finished rendering, the application would crash. This happened a couple of times, also with some smaller files. I successfully managed to replicate it just before writing this report (to get the crash log). It seems to be an issue with the main view trying to scroll the preview view before it has any content. Here is an image of the crash log:

Here is the full log: http://pastebin.com/EenjhawV