What Happened To Disqus? I'm using Drupal 7.38 with the Disqus (version 7.x-1.12) module.

Disqus simply fails to load.  No trace of it in the console, elements or sources.

Disqus visibility is set to appear in  block as per /admin/config/services/disqus and block is configured. Its "permissions" are configured properly also.

Disqus was previously working.
Did you add the disqusapi library to /sites/all/libraries (or a similar location)? This happened to my site. Our Disqus comment block stopped loading on existing nodes, and I could not turn on Disqus comments for new nodes.

Then I noticed the message in the Disqus config (/admin/config/services/disqus) that I needed to have the Libraries module installed and api files.

Once I added those files, the Disqus block loaded again.