Only an absolute URI can be used as a base address

Question

Please help getting exception at using (ServiceHost host = new ServiceHost(typeof(HelloService.HelloService))) in the below code

Exception : Only an absolute URI can be used as a base address

WCF Host Application

    class Program
    {
        static void Main()
        {
            using (ServiceHost host = new ServiceHost(typeof(HelloService.HelloService)))
            {
                host.Open();
                Console.WriteLine("Service Started");
                Console.ReadLine();
            }
        }
    }

Contract Implementation

    public class HelloService : IHelloService
    {
        public string GetMessage(string Name)
        {
            return "Hello" + Name;
        }
    }

Contract

[ServiceContract]
    public interface IHelloService
    {
        [OperationContract]
        string GetMessage(string Name);
    }

App.Config

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <system.serviceModel>
    <services>
      <service name="HelloService.HelloService" behaviorConfiguration="mexBehaviour">
        <endpoint address="HelloService" binding="basicHttpBinding" contract="HelloService.IHelloService">
        </endpoint>
        <endpoint address="HelloService" binding="netTcpBinding" contract="HelloService.IHelloService">
        </endpoint>
        <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange">
        </endpoint>
        <host>
          <baseAddresses>
            <add baseAddress="http://localhost:8080/HelloService"/>
            <add baseAddress="net.tcp//localhost:8090/HelloService"/>
          </baseAddresses>
        </host>
      </service>
    </services>
    <behaviors>
      <serviceBehaviors>
        <behavior name="mexBehaviour">
          <serviceMetadata httpGetEnabled="true"/>
        </behavior>
      </serviceBehaviors>
    </behaviors>
  </system.serviceModel>
</configuration>

Answer 1

I believe you are missing a colon (:):

<add baseAddress="net.tcp//localhost:8090/HelloService"/>

should be

<add baseAddress="net.tcp://localhost:8090/HelloService"/>

Answer 2

<endpoint address="HelloService"...

Should be

<endpoint address="/HelloService"...

See https://msdn.microsoft.com/en-us/library/ms733749(v=vs.110).aspx