I am very familiar with Discourse 
we use it at Nextcloud with quite a big userbase: https://help.nextcloud.com
All the interface elements are pretty standard, so I don’t think there’s anything really to school people about. 
Regarding the issue: I just opened it in a private tab, the issue remains. But we can just see if it’s a timing issue.
Btw, can any admin change the title of the site from »open source design« to »Discourse – Open Source Design«? (Again, small things like this is why we should have multiple admins to prevent bottlenecks.)