2580196 - After installation SAP Disclosure Management, The Application is not responding to logon

After an upgrade of SAP Disclosure Management, you are unable to logon or the application is not responsive.

sample error message in the log:

2017-12-15 21:12:29.0747 [24] [ERROR] ==>

-------- Begin --------

ErrorID: f81312fa-0002-4ec4-a491-b621f171bba3

Error in path: Unknown

Raw url: Unknown

Message: Invalid key

Parameter name: Client-Webservice

Source: cundus.enterpriseReporting.OperationalManagement

Stack trace:    at cundus.enterpriseReporting.OperationalManagement.Configuration.ConfigurationManager.GetConfigurationValue(ConfigSectionType sectionType, String key)

   at cundus.enterpriseReporting.Web.MvcApplication.InitializeApplication()

   at cundus.enterpriseReporting.Web.MvcApplication.Session_Start(Object sender, EventArgs e)

   at System.Web.SessionState.SessionStateModule.CompleteAcquireState()

   at System.Web.SessionState.SessionStateModule.BeginAcquireState(Object source, EventArgs e, AsyncCallback cb, Object extraData)

   at System.Web.HttpApplication.AsyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()

   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

-------- End --------

SAP Disclosure Management 10.X

invalid key, Parameter name,Client-Webservice , KBA , EPM-DSM-INS , Installation , Problem