The University of Wisconsin - Milwaukee has moved to D2L version 10.
Updated help files are located at uwmltc.org
Occasionally, a posting to a discussion forum (or a response to a posting) may appear to be blank.
This situation may be a result of this known issue: https://jira.doit.wisc.edu/KnownIssuesList/RequestController?issueId=43512&stylesheet=knownissues.css
As described in the linked article, removing certain HTML tags from the original posting (using the HTML editor) may resolve the issue. However, it is difficult for most users to find the offending tags and eliminate them in the html view of the editor -- most people don't even know that view exists.
One best practice is for users to compose their D2L Discussion postings in something OTHER than MS Word. Notepad is an easy solution, but since there is no spellcheck, the person who uses Notepad might want to do spellchecking and editing (font, bold, italic, etc) AFTER they paste into D2L.
This known issue is not consistent across all users who copy/paste from Word into the D2L HTML editor, and it doesn't even happen EVERY time for a single user, for some reason, so it is very difficult to prevent and troubleshoot.