I had a file encoded in MacRoman (TextEdit's default default) that had an ellipsis (…) in the middle of it. Trying to view this file with QLMarkdown 1.2 crashed QuickLook.
As it turns out, a file containing a single MacRoman-encoded ellipsis will crash QLMarkdown 1.2.
I'll see if I can't change the relevant bits to use +[NSString stringWithContentsOfURL:usedEncoding:error:] or its -init… counterpart.
This issue seems to be fixed in v1.3.0 following an update to the latest version of the discount markdown engine.
Confirmed resolved in v1.3.2