Plug-ins not showing up

Version 6.5.11 (Build 8754), Sugar Professional

I went to install the Outlook 2013 plug-in on a new PC, and the listing of available plug-ins no longer shows up.  All I get is a note saying "Read about the plug-in features within the Plug-ins Documentation."  Are they temporarily down, or is there something that we could have done that prevents them from showing up now?  They did show up the last time I checked, which was about 2-3 weeks ago.