(1) In Visual Studio. Click On Project –> “ProjectName” Properties as shown in screenshot.
(2) Click On debug Tab & unselect Enable Visual Studio Hosting Process.
Solution – 2
There might be some project configuration problem. SO You can recreate the project & copy old source files to new project.
This problem most probably occurs when you try to run your older projects. If 1st solution does not work then, better recreate entire project to solve all configuration issues.