The type XXXX provided as the service attribute value in the ServiceHost directive could not be found

Because an existing SVC uses MTOM en TEXT was needed I created a second SVC for that.

In the web config it looks like this:

<service behaviorConfiguration="W2DWebserviceBehavior4Core" name="W2DWebservice.W2DWebservice4Core">
    <endpoint binding="wsHttpBinding" bindingConfiguration="CustomAuthentication4Core" contract="W2DWebservice.IW2DWebservice4Core" />
  <host>
    <baseAddresses>
      <add baseAddress="localhost" />
    </baseAddresses>
  </host>
</service>



<wsHttpBinding>
  <binding name="CustomAuthentication4Core" maxReceivedMessageSize="1006710886" messageEncoding="Text" textEncoding="utf-8">
    <readerQuotas maxDepth="2147483647" maxStringContentLength="2147483647" maxArrayLength="2147483647" maxBytesPerRead="2147483647" maxNameTableCharCount="2147483647" />
    <security mode="TransportWithMessageCredential">
      <message clientCredentialType="UserName" negotiateServiceCredential="false" establishSecurityContext="false" />
    </security>
  </binding>
</wsHttpBinding>


<behavior name="W2DWebserviceBehavior4Core"> 
  <serviceMetadata httpGetEnabled="false" httpsGetEnabled="true" />
  <serviceCredentials>
    <userNameAuthentication userNamePasswordValidationMode="Custom" customUserNamePasswordValidatorType="W2DWebservice.W2DWebservice4Core+CustomUserNameValidator, W2DWebservice" />
    <issuedTokenAuthentication allowUntrustedRsaIssuers="true" />
  </serviceCredentials>
  <serviceDebug includeExceptionDetailInFaults="false" httpHelpPageUrl="false" />
</behavior>  

The markup of the SVC file looks like this:

<%@ ServiceHost Language="VB" Debug="true" Service="W2DWebservice.W2DWebservice4Core" CodeBehind="W2DWebservice4Core.svc.vb" %>

When I visit the SVC in the browser on the server I get this error:

The type 'W2DWebservice.W2DWebservice4Core', provided as the Service attribute value in the ServiceHost directive, or provided in the configuration element system.serviceModel/serviceHostingEnvironment/serviceActivations could not be found. 

Locally in Visual Studio it al works perfect. I get the WSDL schema xml there.

Why do I get this error?