Sforzando Issues!

If you run an app as admin you cannot drag and drop onto it.  So if you run SONAR as admin, you can't drag and drop onto plugins.  If you run the stand alone app as admin you can't drag and drop onto it.  (unless the source of the drag is also running as admin I think, not sure on that one)
 
The file->load in the standalone isn't how you import samples.  Click on the Instrument selection box and choose import.  Those menus in the stand alone are for controlling the stand alone plugin instance settings and aren't really part of the sampler engine.
 
Sforzando 1.916 seems to work for me.  Though the stand alone binary does have a version stamp of 1.6.0.5 and the DLLs have versions of 1.8.7.3.  Inside sforzando though the settings page says it's version 1.916 with ARIA engine 1.916.

It seems to import sf2 files for me and sfz files.  Perhaps you need to configure where to store user imports?  Since it doesn't load those file formats, it imports and converts them.  Then saves them in it's native format.  So when I drop a sf2 onto it, it shows up in the User section.  Which I think it saves to disc somewhere.
 

Thanks. It works now but not so straight forward.

You can even change the skin as all graphic files are in the GUI folder.