Dynamics AX 2009 Workflow does not working

I have faced a problem today at my work, the workflow does not working, and there not PR submitted and any incident is Pending.

I checked every thing and restart AOS Service  but my Issue is not fixed, so I checked Windows event log on server that host Workflow services and I got the bellow error.

 

Session log on for Microsoft Dynamics failed.

Dynamics Adapter LogonAs failed.

Microsoft.Dynamics.Framework.BusinessConnector.Session.Exceptions.FatalSessionException
   at Microsoft.Dynamics.Framework.BusinessConnector.Session.DynamicsSession.HandleException(String message, Exception exception, HandleExceptionCallback callback)
   at Microsoft.Dynamics.Framework.BusinessConnector.Session.DynamicsBase.HandleExceptionInternal(String message, Exception e)
   at Microsoft.Dynamics.Framework.BusinessConnector.Session.DynamicsAdapter.LogonAs(String user, String domain, NetworkCredential bcProxyCredentials, String company, String language, String objectServer, String configuration)
   at Microsoft.Dynamics.Framework.BusinessConnector.Session.DynamicsAdapter.Microsoft.Dynamics.Framework.BusinessConnector.Adapter.IAxaptaAdapter.LogonAs(String user, String domain, NetworkCredential bcProxyCredentials, String company, String language, String objectServer, String configuration)
   at Microsoft.Dynamics.Framework.Workflow.BusinessConnector.WorkflowSession.OnLogon(IAxaptaAdapter axaptaAdapter)
   at Microsoft.Dynamics.Framework.BusinessConnector.Session.DynamicsSession.Init(ICacheContext context)

Microsoft.Dynamics.BusinessConnectorNet.LogonFailedException
   at Microsoft.Dynamics.BusinessConnectorNet.Axapta.Logon(BC_PROXY_ACCOUNT_INFO* pBCProxyAccountInfo, String company, String language, String objectServer, String configuration)
   at Microsoft.Dynamics.BusinessConnectorNet.Axapta.LogonUsingBCProxyAccount(_SEC_WINNT_AUTH_IDENTITY_W* pImpersonatedUserAccount, NetworkCredential bcProxyCredentials, String company, String language, String objectServer, String configuration)
   at Microsoft.Dynamics.BusinessConnectorNet.Axapta.LogonAs(String user, String domain, NetworkCredential bcProxyCredentials, String company, String language, String objectServer, String configuration)
   at Microsoft.Dynamics.Framework.BusinessConnector.Session.DynamicsAdapter.LogonAs(String user, String domain, NetworkCredential bcProxyCredentials, String company, String language, String objectServer, String configuration)

Solution:

Restart IIS service on the server.