Question

I don’t get it… I have a WCF Windows service that I can’t manage to call anymore… I always get this error :

Could not load file or assembly ‘Microsoft.VisualBasic,
Version=8.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a’ or
one of its dependency. Access is denied

This stuff was working perfectly until a few days ago when I did some tweaking. Now I can’t get rid of it, no matter what I do.

Service configuration file is :

<system.serviceModel>
  <services>
    <service name="myService"
             behaviorConfiguration="TransfertServiceBehavior">
      <host>
        <baseAddresses>
          <add baseAddress="net.tcp://localhost:8097/MyService"/>
        </baseAddresses>
      </host>
      <endpoint address=""
                binding="netTcpBinding"
                bindingConfiguration="TransactionalBinding"
                contract="myContract" />
      <endpoint address="mex"
                binding="mexTcpBinding"
                contract="IMetadataExchange" />
    </service>
  </services>
  <bindings>
    <netTcpBinding>
      <binding name="TransactionalBinding" transactionFlow="true" transferMode="Streamed"
               maxReceivedMessageSize="1000000000">
         <readerQuotas maxDepth="10000" maxStringContentLength="1000000000"
                       maxArrayLength="1000000000" maxBytesPerRead="10000" 
                       maxNameTableCharCount="10000" />
         <security mode="Transport" />
      </binding>
    </netTcpBinding>
  </bindings>
  <behaviors>
    <serviceBehaviors>
      <behavior name="TransfertServiceBehavior">
        <serviceMetadata httpGetEnabled="False"/>
        <serviceDebug includeExceptionDetailInFaults="False"/>
      </behavior>
    </serviceBehaviors>
  </behaviors>
</system.serviceModel>

While client configuration is here :

<system.serviceModel>
  <bindings>
    <netTcpBinding>
      <binding name="NetTcpBinding_SI6ISupportTransfert" closeTimeout="00:01:00"
               openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00"
               transactionFlow="true" transferMode="Streamed" 
               transactionProtocol="OleTransactions"
               hostNameComparisonMode="StrongWildcard" listenBacklog="10"
               maxBufferPoolSize="524288" maxBufferSize="65536" maxConnections="10"
               maxReceivedMessageSize="65536">
         <readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384"
                       maxBytesPerRead="4096" maxNameTableCharCount="16384" />
         <reliableSession ordered="true" inactivityTimeout="00:10:00"
                          enabled="false" />
         <security mode="Transport">
            <transport clientCredentialType="Windows" protectionLevel="EncryptAndSign" />
            <message clientCredentialType="Windows" />
         </security>
      </binding>
    </netTcpBinding>
  </bindings>
  <client>
     <endpoint address="net.tcp://localhost:8095/myService"
               binding="netTcpBinding" 
               bindingConfiguration="NetTcpBinding_SI6ISupportTransfert"
               contract="myContract" name="mySevice">
         <identity>
            <userPrincipalName value="user@myDomain" />
         </identity>
     </endpoint>
  </client>
</system.serviceModel>

Any idea on what could cause this “Access denied” exception ???

Answer 1

The error is “Access Denied” when loading one of the .net framework dll’s.

It could be several things:

• That version of the .net framework has been removed from the server
• The user which is the identity of the server does not have access to the framework dll’s
• The password of the user which is the identity of the server has expired.
• The password of the user which is the identity of the server has changed.

Try stopping and starting the service to check the password.

Try reinstalling the service to check the .net framework version.