Missing Project File

I work with Robohelp 8 creating a variety of projects (html webhelp etc.) in Windows Vista.

I opened Robohelp today, selected my most current project (wip) and a blank screen came up.

(The files exist on my hard drive, however, the project file returns a blank screen.)

I tried to open the project file using File/Open and got the same results.

I tried to open a few other previously completed RH8 projects, with the same results.

Is there someway to 're-create' the project file or do I have to import all the html files and images?

Thanks.