If you are running Notes 8.5.2 with Fix Pack 2, apparently a fix to the Connections code in Fix Pack 2, broke the Files and Status plugins, from the technote:
I recently installed the Lotus Connections plugins for Files, and Status Updates in my Lotus Notes 8.5.2 client. If you use Lotus Connections and Lotus Notes you need to look at these plugins. I put together a couple of slides that show the installation process, which is really easy, and highlights some of the functionality. Go ahead and try them yourself.
I have been using Document Viewer from OpenNTF for a while now, today John Head posted about a new sidebar plug-in for Notes 8 which automatically displays the document properties, in a format that is much easier to read then natively in Notes. John also provides excellent detailed instructions for installing the plug-in. Here is a screen shot from my sidebar. Thanks John and “Mr Frunobulax” One interesting note, I originally tried to install this from my office where I require a proxy to get out to the internet, when I tried to update, it could not find any updates, when I came home and tried it immediately found and installed the plug-in, this makes me believe that the plug-in install engine does not read the proxy setting from the location doc (other sidebar plug-ins do not honor the location document settings either). I will have to do a little more testing on this.