Viewer pane volume bar missing

I have finally upgraded to dopus 12 and have noticed that my volume bar is missing in the viewer pane. There is not option in the viewer pane to control volume, and I must control it thorough windows. Will someone please tell me how to get it back?
Thank you

Which file format are you viewing?

Which viewer is being used for it? It should say next to the filename at the top of the viewer pane (if the pane is made wide enough).