I previously had this issue. It only affects admins who have the rights to change the order of the pinned topics which is why it's unlikely others can't reproduce on the OPs site.
However since 1.7 (could be Chrome 64) I no longer have the problem.
[Solved] markdown not working on my fresh install
I just set up nodebb on an amazon ec2 instance (ubuntu 14) and am not having any luck with markdown. My paragraphs are all running together and my chrome console is reporting:
Uncaught Error: Syntax error, unrecognized expression from nodebb.min.js
Preview tab results in the same error as above and is blank.
EDIT: with a fresh install, it's working.