Exception of type 'Microsoft.SharePoint.SoapServer.SoapServerException' was thrown when calling WebPartPagesWebService.AssociateWorkflowMarkup

hi all

how are you

i have an application page on sharepoint that contains three buttons

the first button creates the workflow.xoml,workflow.xoml.rules and workflow.xoml.wfconfig.xml files

the second button add a folder containing these files to the Workflows document library on sharepoint

the third button calls the WebPartPagesWebService.ValidateWorkflowMarkupAndCreateSupportObjects and WebPartPagesWebService.AssociateWorkflowMarkup methods

everything works fine when i press the first and the second button

the problem happens when i press the third button where it reaches the WebPartPagesWebService.AssociateWorkflowMarkup method it gives this error:

Exception of type 'Microsoft.SharePoint.SoapServer.SoapServerException' was thrown.

and i search for more details inside the error and i get that the StackTrace is

   at System.Web.Services.Protocols.SoapHttpClientProtocol.ReadResponse(SoapClientMessage message, WebResponse response, Stream responseStream, Boolean asyncCall)
   at System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke(String methodName, Object[] parameters)
   at WorkflowWebApplication.sharepointdev1.WebPartPagesWebService.AssociateWorkflowMarkup(String configUrl, String configVersion)


does anyone know why i am getting this error