Visual Studio Solution Unavailable (reload doesn't work)

Question

I am downloading a sample program for a barcode reader that I am using. Everytime I download the program and run it I am prompted with the error in my solution explorer (see ima

Answer 1

Had similar problem with causing solution explorer to indicate file "unavailable". Performed same fix as suggested above i.e. right clicked on file and selected reload. Got another message that in order run in Universal window had to install what was being offered which I did and everything working fine now.