I as well am having the same "UserID is not valid" message:
2015-11-10 09:07:34,951 [1] INFO CdsAssessment.ViewModel.ReportsViewModel - Requests status updating.
2015-11-10 09:07:34,966 [1] INFO CdsAssessment.ViewModel.ReportsViewModel - ReportsViewModel.UpdateReports()
2015-11-10 09:07:34,966 [1] INFO CdsAssessment.ViewModel.ReportsViewModel - Adding report requests.
2015-11-10 09:07:49,273 [1] INFO CdsAssessment.ViewModel.ReportsViewModel - ReportsViewModel.UpdateReports()
2015-11-10 09:07:49,273 [1] INFO CdsAssessment.ViewModel.ReportsViewModel - Adding report requests.
2015-11-10 09:07:51,132 [1] INFO CdsAssessment.ViewModel.ReportsViewModel - ReportsViewModel.UpdateReports()
2015-11-10 09:07:51,132 [1] INFO CdsAssessment.ViewModel.ReportsViewModel - Adding report requests.
2015-11-10 09:09:49,790 [7] ERROR SolarWinds.CDS.Engine.CDSEngine - SubmitCDSReportRequest failed:System.Web.Services.Protocols.SoapException: UserId is not valid
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 PartyRegistrationService_2_0.registerParty_2_0(PartyRegistrationRequest partyRegReq)
at SolarWinds.CDS.Engine.CDSRegistrationFlow.Register(String& res)
at SolarWinds.CDS.Engine.CDSEngine.SubmitCDSReportRequest(String userId)
2015-11-10 10:11:40,621 [1] INFO CdsAssessment.ViewModel.ReportsViewModel - ReportsViewModel.UpdateReports()
2015-11-10 10:11:40,621 [1] INFO CdsAssessment.ViewModel.ReportsViewModel - Adding report requests.
2015-11-10 10:11:42,074 [1] INFO CdsAssessment.ViewModel.ReportsViewModel - ReportsViewModel.UpdateReports()
2015-11-10 10:11:42,074 [1] INFO CdsAssessment.ViewModel.ReportsViewModel - Adding report requests.
2015-11-10 10:20:52,294 [5] ERROR SolarWinds.CDS.Engine.CDSEngine - SubmitCDSReportRequest failed:System.Web.Services.Protocols.SoapException: UserId is not valid
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 PartyRegistrationService_2_0.registerParty_2_0(PartyRegistrationRequest partyRegReq)
at SolarWinds.CDS.Engine.CDSRegistrationFlow.Register(String& res)
at SolarWinds.CDS.Engine.CDSEngine.SubmitCDSReportRequest(String userId)