UnknownError: Hosting the VS2013 SPA template not in IIS root but subfolder

After deploying the VS2013 SPA template application including performed database schema changes the login resp. register form shows "unknown error occured" or "Unbekannter Fehler".

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Because the deployment process was successful I tried then to dissect this issue: 

 

 

https://katanaproject.codeplex.com/workitem/158

http://blogs.msdn.com/b/webdev/archive/2013/09/20/understanding-security-features-in-spa-template.aspx?PageIndex=2#comments