Please help, my package no longer runs saying that a class library can't be run

Please help, I have created a vs 2013 package. All was working fine until I decided to renamed some of my projects and my solution.

Now when I open my solution, I can't run my package as it gives me the error that a project with type class library cannot be run.

I don't know why it no longer runs like a package!?

Any guidance would be appreciated.