A call to SPPI failed, see inner exception.

Out of nowhere we started receiving the following error on our EP/Sharepoint server.  It didn't seem to coincide with any events such as Windows Updates, code deployment, etc.

After searching, I found the the .axc files that EP and SSRS were using had been updated the day before this error showed up.  Not sure who or what updated them but it appeared they had their WCF Regenerated, only incorrectly.

I had the original .axc files so we simply replaced the bad ones with the known working versions, rebooted the EP and SSRS servers, and everything has worked great since!

I suspect we could have also done the 'Refresh' from the Config utility and that would have also worked.

A call to SSPI failed, see inner exception.

Microsoft.Dynamics.AX.Framework.Services.Client.UserSessionServiceException
at Microsoft.Dynamics.AX.Framework.Services.Client.ServiceClientHelper.InvokeChannelOperation[TResult,TChannel](IServiceClient`1 client, Func`2 operationInvoker, Func`2 exceptionWrapper)
at Microsoft.Dynamics.AX.Framework.Services.Client.UserSessionClient.GetAccessRights(IEnumerable`1 keys)
at Microsoft.Dynamics.Framework.Portal.UI.WebControls.WebParts.ReportMenuItemHelper.HasAccess(MenuItemKey menuItemKey)
at Microsoft.Dynamics.Framework.Portal.UI.WebControls.WebParts.AxReportViewerInternal.HasAccessToOutputMenuItemIfRequired()
at Microsoft.Dynamics.Framework.Portal.UI.WebControls.WebParts.AxReportViewerInternal.CanPreRender()
at Microsoft.Dynamics.Framework.Portal.UI.WebControls.WebParts.AxReportViewerInternal.OnPreRender(EventArgs e)

A call to SSPI failed, see inner exception.

System.ServiceModel.Security.SecurityNegotiationException

Server stack trace: 
at System.ServiceModel.Channels.WindowsStreamSecurityUpgradeProvider.WindowsStreamSecurityUpgradeInitiator.OnInitiateUpgrade(Stream stream, SecurityMessageProperty& remoteSecurity)
at System.ServiceModel.Channels.StreamSecurityUpgradeInitiatorBase.InitiateUpgrade(Stream stream)
at System.ServiceModel.Channels.ConnectionUpgradeHelper.InitiateUpgrade(StreamUpgradeInitiator upgradeInitiator, IConnection& connection, ClientFramingDecoder decoder, IDefaultCommunicationTimeouts defaultTimeouts, TimeoutHelper& timeoutHelper)
at System.ServiceModel.Channels.ClientFramingDuplexSessionChannel.SendPreamble(IConnection connection, ArraySegment`1 preamble, TimeoutHelper& timeoutHelper)
at System.ServiceModel.Channels.ClientFramingDuplexSessionChannel.DuplexConnectionPoolHelper.AcceptPooledConnection(IConnection connection, TimeoutHelper& timeoutHelper)
at System.ServiceModel.Channels.ConnectionPoolHelper.EstablishConnection(TimeSpan timeout)
at System.ServiceModel.Channels.ClientFramingDuplexSessionChannel.OnOpen(TimeSpan timeout)
at System.ServiceModel.Channels.CommunicationObject.Open(TimeSpan timeout)
at System.ServiceModel.Channels.ServiceChannel.OnOpen(TimeSpan timeout)
at System.ServiceModel.Channels.CommunicationObject.Open(TimeSpan timeout)
at System.ServiceModel.Channels.ServiceChannel.CallOnceManager.CallOnce(TimeSpan timeout, CallOnceManager cascade)
at System.ServiceModel.Channels.ServiceChannel.EnsureOpened(TimeSpan timeout)
at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout)
at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation)
at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message)