Hi
I can't use the multiview plugin, because the associated .dll file was not found.
But multiview.dll exists. See attachments please.
Regards
That plugin lets you use certain 3rd party viewers, but the viewers themselves don't come with Opus.
Since you are on Vista (not XP or earlier), you are better off getting QuickViewPlus 11 (see thread about it in the plugins area) which will give you the same viewers that multiview.dll was used for in the past, but packaged as preview handlers which will work in Opus, Office, Explorer, etc. with minimal hassle.
(Miltiview can still be useful on XP, where the QVP11 preview handlers aren't an option, and for people who already have the 3rd party viewers via some other method. Since neither apply to you, QVP11 is the easiest way to get the extra viewers).
But also note that Opus can view most common file formats without multiview or QVP. Most people don't have or need either, but if you need to view certain special formats then they can be useful.
Thank you very much. 
Thx for your fast answer 
Regards