The Autodesk discussion groups are currently working. They are also still irresponsibly displaying people’s email addresses as visible user names. If you’ve posted to the discussion groups in the past, I suggest you check to see if your email address is out there for the spambots to pick up.
There is now a feedback form for the discussion group and Community sites, so if you’re having problems you could try that. Hopefully, Autodesk won’t need a thousand feedback reports to work out that it’s running as slow as a wet week, the search is broken and that people’s privacy has been violated.
If you have links to product categories that no longer work properly, you can modify the format as shown in this example, which is for the AutoCAD category.