Thinking...
It is possible to get Plogue in a confused state where processing off=on and on=off, spam first selecting an audio device that is in use by another process and then switching to one that isn't, but If you are starting plogue from scratch repeatedly that is unlikely.
Maybe start with a layout that has only an audo file player and your audio device in it and make sure that is working. The default layout that comes up when you start plogue should be good (player, mixer, and default audio device)
If that doesn't work you could try re installing Plogue from this link:
http://www.plogue.com/download/PlogueBi ... taller.exeand then re-installing Spec.
That will pull down the latest version of Plogue.
That said, these are kind of "shotgun" fixes and I suspect we are missing something, but please try these and report back.
Cheers,
Z