在这里找到解决方案

http://social.msdn.microsoft.com /论坛/ EN / lightswitchgeneral /线程/ cb543510-fe9e-4da9-941c-44c470ffbce5

I get a login popup when I try to run the application. It says windows security in the popup title. When I enter my windows credentials I get 403 screen. I am using forms authentication in my app so I don't know why I get this. Any ideas?

THanks

found solution here

http://social.msdn.microsoft.com/Forums/en/lightswitchgeneral/thread/cb543510-fe9e-4da9-941c-44c470ffbce5