Thanks for the advice, Jon. I reinstalled X1 and Opus is now "viewing" just fine.
I think what happened is that the problem originally arose when I upgraded to Opus v 9.1, which initially had a defective version of Multiview (see this thread: resource.dopus.com/viewtopic.php ... tiview+dll).
In an attempt to troubleshoot the problem I uninstalled X1, which I had not been using. Then when I downloaded the fixed Multiview.dll file and put it in the Opus plugin folder the Stellent filters weren't available.
If it is not too much trouble, could you provide a further explanation of the Opus viewer system?
First, in my experience with programs that used plugins (which includes things like browsers and audio file editors), the plugin is a single file which is dropped into the main program's "plugins" folder, and voila, things work. In the case of Opus, additional "Stellent viewers" are needed.
Just what are the "Stellent viewers?" (Although you use the term Stellent "viewers" they are actually installed in a "filters" folder, which on my system contains 198 files.)
Why are the "Stellent" viewers needed; that is, why isn't Multiview.dll sufficient? How does Stellent and Multiview.dll. interact?
Second, I've used third-party file managers for many years, and if I remember right they always were able to easily preview files, especially such common formats as DOC and WordPerfect WPD. Opus is by far the most powerful file manager I've ever used, and yet it's viewing capabilities seem limited. Why not just provide all the viewing capability with the program, rather than requiring the user to find a set of third-party files? Why is this so complicated?
Thanks again.