The project file contains a property value that is not valid – WPF error
While developing a WPF application I had created a new project in my solution. I then copied several pages from one project to the new project. On running the application I got the wierd error “The project file contains a property value that is not valid”. I checked the files and codebehind over and over without finding the problem.
Eventually the problem turned out to be the build action for the pages that I had copied! aaargh. They had been set to “ApplicationDefinition”, setting them back to “Page” solved the problem. Other files like images etc show similar issues so be aware of this!!