Synchronisation - Nullable object must have a value?

Hi,

There was a problem with the Outlook/Office365 synchronisation that started recently. It started to give errors with a message like "Nullable object..."

We have investigated it and it seems Microsoft created a bug in their public Outlook API.

We have created a fix/workaround in the software, please update to the latest OneCalendar version from the store to resolve this issue:
- Windows OneCalendar version 2023.310.1.0 or higher
- Android OneCalendar version 4.3.5 or higher
- iOS OneCalendar version 4.4 or higher
- macOS OneCalendar version 4.4 or higher

Sorry for any inconvenience.

Have a good day!

OneCalendar Team

Hi,

This is a problem that started recently. We have investigated it and it seems Microsoft created a bug in their Outlook API. We have reported it to them and we are currently trying to create a solution/workaround as soon as possible.

Sorry for any inconvenience.

Hi same problem on WINDOWS, ANDROID AND IOS

Nullable object must have a value.

System.InvalidOperationException: Nullable object must have a value.

   at System.ThrowHelper.ThrowInvalidOperationException_InvalidOperation_NoValue() + 0x2d

   at System.Nullable`1.get_Value() + 0x12

   at CalendarApp.MicrosoftGraphProvider.CachedMicrosoftAppointment.ExpandAllOccurrences(DateTime, DateTime) + 0x2a7

   at CalendarApp.ProviderBase.CachedAppointment`1.ExpandReccurence(DateTime, DateTime) + 0x1a

   at CalendarApp.ProviderBase.AccountProviderBase`9.UpdateExpandedDataForAppointment(Transaction, TCachedAppointment) + 0x14a

   at CalendarApp.ProviderBase.AccountProviderBase`9.UpdateAppointmentAndExpanded(Transaction, TCachedAppointment) + 0xcc

   at CalendarApp.MicrosoftGraphProvider.MicrosoftGraphAccount.<SyncReceiveCalendarFromProvider>d__7.MoveNext() + 0xb10

--- End of stack trace from previous location where exception was thrown ---

   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() + 0x21

   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task) + 0x70

   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task) + 0x38

   at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task) + 0x17

   at CalendarApp.MicrosoftGraphProvider.MicrosoftGraphAccount.<SyncReceiveCalendarFromProvider>d__6.MoveNext() + 0x2e2

--- End of stack trace from previous location where exception was thrown ---

   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() + 0x21

   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task) + 0x70

   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task) + 0x38

   at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task) + 0x17

   at System.Runtime.CompilerServices.TaskAwaiter.GetResult() + 0xb

   at CalendarApp.ProviderBase.AccountProviderBase`9.<SyncReceiveCalendar>d__99.MoveNext() + 0x21b