C# – Unable to access WCF service using NET.TCP binding

I already asked a similar question here: Unable to add service client for a net.tcp WCF service. The problem was solved at that time. But now the same error is coming up. My configuration of WCF service is same as that of previous question. I am again posting it here:

<system.serviceModel>
    <services>
      <service name="CoreService.Service1" behaviorConfiguration="beh1">
        <host>
          <baseAddresses>
            <add baseAddress="net.tcp://localhost/Service1.svc/mex" />
          </baseAddresses>
        </host>
        <endpoint
     binding="netTcpBinding"
     bindingConfiguration="ultra"
     contract="CoreService.IAccountService"/>
        <endpoint
      binding="netTcpBinding"
      bindingConfiguration="ultra"
      contract="CoreService.IBoardService"/>
        <endpoint
      binding="netTcpBinding"
      bindingConfiguration="ultra"
      contract="CoreService.ICategoryService"/>

        <endpoint
                address="mex"
                binding="mexTcpBinding"
                contract="IMetadataExchange"/>
      </service>
    </services>
    <bindings>
      <netTcpBinding>
        <binding name="ultra"
             maxBufferPoolSize="2147483647"
             maxBufferSize="2147483647"
             maxReceivedMessageSize="2147483647"
             portSharingEnabled="false"
             transactionFlow="false"
             listenBacklog="2147483647"
             sendTimeout="00:01:00">
          <security mode="None">
            <message clientCredentialType="None"/>
            <transport protectionLevel="None" clientCredentialType="None"/>
          </security>
          <reliableSession enabled="false"/>
        </binding>
      </netTcpBinding>
    </bindings>
    <behaviors>
      <serviceBehaviors>
        <behavior name="beh1">
          <serviceMetadata httpGetEnabled="false" />
          <serviceDebug includeExceptionDetailInFaults="True" />
          <dataContractSerializer maxItemsInObjectGraph="65536" />
        </behavior>
      </serviceBehaviors>
    </behaviors>
  </system.serviceModel>

The error is:

The URI prefix is not recognized. Metadata contains a reference that
cannot be resolved: 'net.tcp://localhost/Service1.svc'. Could not
connect to net.tcp://localhost/Service1.svc. The connection attempt
lasted for a time span of 00:00:02.0051147. TCP error code 10061: No
connection could be made because the target machine actively refused
it 127.0.0.1:808. No connection could be made because the target
machine actively refused it 127.0.0.1:808 If the service is defined in
the current solution, try building the solution and adding the service
reference again.

After the problem was solved, I didn't made any changes to the configuration and after some days it started showing that error again. I tried everything but nothing worked. Please help!

UPDATE: I am also able to access it using HTTP through my browser but unable to access using "Add Service Reference" option through net.tcp protocol.