I experienced a runtime error recently when attempting to view a RH topic using View Selected Item. After the error, the preview window will not display. I found this forum post - http://forums.adobe.com/message/3385197 - and tried the suggested solution, but to no avail. I have restarted my laptop, closed and reopened the project, and renamed by cpd file. What else can I try? I need the window.
So, I normally work with an extended desktop, but was working from home exclusively on my laptop when this issue occured. When I got in to work and moved to dual screens, lo and behold there's my preview window.
Thank you, Peter, for following up.