Obtaining Disqus Shortname
To obtain Disqus Shortname register at https://disqus.com/profile/signup/
After you login select “I want to install Disqus on my site”
Fill the form and click “Create Site”.
The field “Website Name” is your SHORTNAME. Copy that in your clipboard. Paste it in the Stachethemes General Settings Disqus Shortname.