You may see the following error message from Disqus when viewing a Disqus lesson:
"We were unable to load Disqus. If you are a moderator please see our troubleshooting guide."
If so, you can find Disqus' troubleshooting guide here.
This is because the URL has changed and Disqus doesn't know how to connect anymore. You'll need to remap the URLs in Disqus. They have some instructions for that here: https://help.disqus.com/customer/portal/articles/912757-url-mapper
If that seems like a bit too much, you can disconnect and reconnect Disqus however, please note that this will result in all of your previous Disqus discussion posts being wiped clean.