Below you can find manual on how to report bugs, please read it first before report some bug.
1 Login/Register to github.com.
2 Go to the "Issues":
3 Click on "New issue"
4 Post title of the bug (The name of Quest, spell, object, NPC, etc.) in the "Title".
5. In the "Leave a comment" describe carefully encountered error. Provide ID of Quest / Spell / object / NPC Which does not work, where it is, the description of how it should work (as shown below)
6 After the above steps, click on the "Submit new issue."
7. Congratulations! Reported an error! Now you have to wait for fix ;)
ID can be find on the wowhead.com type the name of the spell, quest, item, etc. After searching the object ID can be taken from the link which was generated, for example: http://www.wowhead.com/item= 124228/Desecrated-Shadowmoon-insignia&bonus=0, so in this case, the ID of an item "Desecrated Shadowmoon Insignia" is 124228 .