If I open multiview with Execute (amiga-E) from workbench and load a text file from a requester, the text file loads properly. I then use Workbench to go to another file and drag that icon into the multiview window, multiview will not respond to open up file and I get a error message in title bar saying icon cannot be dragged into this window.
However, if I again load a text file via the "Open" menu item in multiview, I can load a new text file. And then if I drag an icon into this window, it works!