Go to any wiki page and try to print, it will give an error message that print preview failed. Shows 0 pages to print.
Possibly related to scroll bar shiz.
From IRC:
robk: epriestley: is there something wrong with the phabricator, we can't print anymore inside of wiki, it's totally broken, if we remove a certain set of classes, it works again, I'm trying to make a simple hack to fix for my team printing, but I can't do anything to phab, something is up w/ the debug console. Was phab written to prevent usage of any external scripts?..