Tuesday, 21 June 2011

HTTP Error 503: Service unavailable

  1. Go to the respective application pool in IIS and check whether the service is running or not. If not start the service. 
  2. If the service is getting stopped and got the same error when you browse the server. Check the Identity credentials in advanced settings of the application pool.It may cause due to change of the system credentials.


  1. Thanks for that it got me pointed in the right direction.
    The identity credentials were correct when I looked them up on the application pool but it still failed as you described under point 2.
    To get it working I needed to re-enter the identity credentials and do a IISRESET to get it working.

  2. I've installed WS Services on AX 2012 CU6 with all defaults in the setup wizard. It registered a web site in AX which I used to create an enhanced HTTP inbound port for a custom AIF service. The port activated with flying colors, however when I use Visual Studio to add reference to my service or simply entering the WSDL URI in the browser window I'm getting the dreaded 503 service unavailable. Steps above didn't help. The app pool stops as soon as it enters running state. There is an error in windows app log "An error occurred while executing Preload method. Exception: System.InvalidOperationException Message: An error occurred while trying to create preload provider 'Microsoft.Dynamics.Ax.Services.Host.AxServiceAutoStartProvider, Microsoft.Dynamics.IntegrationFramework.WebService.Process' Exception: System.TypeLoadException Message: Could not load type 'Microsoft.Dynamics.Ax.Services.Host.AxServiceAutoStartProvider' from assembly 'Microsoft.Dynamics.IntegrationFramework.WebService.Process'. StackTrace: (stack follows) ... "

  3. Thanks a lot .. working fine after change the identity and credentials

  4. Thank you been of great help for me

  5. Good tip Shankar. Helped me more than one occasions. Thank you.