We're seeing multiple clients of ours experiencing outlook crashing after upgrading Outlook to any of the November 9th updates across at least two of the update channels (Monthly Enterprise 2209 (15629.20258) and Semi-Annual Enterprise: 2202 (14931.20806)). We're still in the investigation phase of trying to determine root cause, but we have some data at this point.
The EventViewer error is:
Faulting application name: OUTLOOK.EXE, version: 16.0.15629.20258, time stamp: 0x63603097 Faulting module name: ucrtbase.dll, version: 10.0.19041.789, time stamp: 0x2bd748bf
Sometimes it is ntdll.dll instead of ucrtbase.dll
We've gotten a couple crash dumps from one of our customers and the line that throws exceptions are different, but they're also rather innocent. In one place we do this:
Dim propertyAccessor As Microsoft.Office.Interop.Outlook.PropertyAccessor = mail.PropertyAccessor
and the other:
Dim mail As Microsoft.Office.Interop.Outlook.MailItem = TryCast(item, Microsoft.Office.Interop.Outlook._MailItem)
We use Add-in Express and in both those cases, the callstack shows our code being called from:
AddinExpress.MSO.2005.dll!AddinExpress.MSO.ADXOutlookAppEvents.DoExplorerSelectionChange(object explorer) AddinExpress.MSO.2005.dll!AddinExpress.MSO.ADXAddinModule.OlExplorerEvents_10_SinkHelper.AddinExpress.MSO.IExplorerEvents_10.SelectionChange()
Finally, the exception in the dump files from the customer is:
Unhandled exception at 0x00007FFF720BC67F (ntdll.dll) in OUTLOOK.EXE.7468.dmp: Indirect call guard check detected invalid control transfer.
Does anyone know how a variable assignment or a TryCast could trigger a Control Flow Exception? Or any steps we could do to get more information about the root cause?
Just wanted to follow up on this as I hate un-followed up questions on StackOverflow. :) The problem "went away" over time. I'm assuming it was addressed in an Outlook update - but I haven't been able to track down any mention of it in the release notes. We did work with a Microsoft Support Engineer on it, but it was first line support so not much came out of it.