Hello! I did not know where to write, so I write here. When you try to create a book .pdf in Wiki, the site after add & click to “Download as PDF” gives an error for the past few days. Before everything worked perfectly.
Administrators can delete this topic, I just tell the function to create a wiki book in PDF- not working.
Add wiki http://wiki.mikrotik.com/wiki/Category:Manual 257 pages
Then click “Download as PDF” and… 
Same problem for a long time.