Failed to Invoke the WCF Service

Hello,

i created a wcf web service. my service uses EF5 data acceess to fetch data.

i have only one function named GetAllAdminList()

IAdminService.cs

 public interface IAdminService {

       [OperationContract]

        List<TblAdmin> GetAllAdminList();

And AdminService.svc.cs

 public class AdminService : IAdminService

            public List<TblAdmin> GetAllAdminList()

               AdminJobBal adminBal = new AdminJobBal();

               return adminBal.GetAllAdminList();

Here the code part is returning the listofAdminUser from database.

Now When i am invoking the service on setting service as startup project and AdminService.svc.cs as startup page it throws me a error

An error occurred while receiving the HTTP response to "localhost:13001/AdminService/AdminService.svc" This could be due to the service endpoint binding not using the HTTP protocol. This could also be due to an HTTP request context being aborted by the server (possibly due to the service shutting down). See server logs for more details.

i can assure u that my data access code works,bcoz i dubug that project and i saw that it return the List perfectly! the problem occures AFTER the return value of List

to check And also i have an another svc that

 public class Service1 : IService1 { public string GetName(string Name) { return "hello" + Name; }  }

when i make it startuppage it's invoking fine and returning the string.

TblAdmin Entity is like this

public class TblAdmin

{

public TblAdmin();

public int AdminId { get; set; }

public string AdminName { get; set; }

public string AdminPassword { get; set; }

public string AdminUserName { get; set; }

public string ContactNumber { get; set; }

public DateTime CreatedOn { get; set; }

public string Description { get; set; }

public bool IsActive { get; set; }

public bool IsDeleted { get; set; }

public virtual ICollection TblCities { get; set; }

public virtual ICollection TblCompanies { get; set; }

public virtual ICollection TblCountries { get; set; }

public virtual ICollection TblJobs { get; set; }

public virtual ICollection TblJobTypes { get; set; }

public virtual ICollection TblSkillGroups { get; set; }

public virtual ICollection TblSkills { get; set; }

public virtual ICollection TblStates { get; set; }

}

and my web config file is like this

Don't know what is the main problem,please help me to resolve it.