Error message when you test Microsoft Dynamics AX settings in the Dynamics AX Connector: "Object reference not set to an instance of an object"

Update the AX web.config file by following these steps:

1. Open the web.config file located at the following location:
C:\Program Files\Microsoft Dynamics AX\50\AifWebServices.

2. Remove the <httpModules> section because these modules are already registered.

3. Update the file to configure the services to all use wsHttpBinding:

  <system.serviceModel>
    <bindings>
      <basicHttpBinding>
        <binding name="basicHttpBindingWindowsAuth">
          <security mode="TransportCredentialOnly">
            <transport clientCredentialType="Windows" />
          </security>
        </binding>
      </basicHttpBinding>
   <wsHttpBinding>
   <binding name = "wsHttpWindowsAuthAif" />
   </wsHttpBinding>
    </bindings>
   
    <services>
      <service behaviorConfiguration="serviceBehaviorConfiguration"
        name="Microsoft.Dynamics.IntegrationFramework.Service.AssetConditionService">
        <endpoint address="" binding="wsHttpBinding" bindingConfiguration="wsHttpWindowsAuthAif"
          bindingNamespace="http://schemas.microsoft.com/dynamics/2008/01/services"
          contract="Microsoft.Dynamics.IntegrationFramework.Service.CustomerService" />
      </service>
    </services>