Calendar sync errors - started on 3/8/23

Hi,

There is a problem with the Outlook/Office365 synchronization that started recently. It occurs when an instance of a series appointment is changed. 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.

The OneCalendar team

I'm having the same issue, also started a few days ago.

Error message/title:
System.InvalidOperationException: Nullable object must have a value.

Please help. Ty.

Please FIX THIS! My work meetings are not syncing and I'm missing meetings. Been using this for years and now it's not working . I will have to look for another resource if you can't resolve this ASAP.

It seems to be working for me now. I launched the app on my Win10 desktop and all my appointments are displaying correctly, without sync errors. However, I needed to uninstall/reinstall my droid app to get it to work correctly. Now I'm back in business! Thank you to the OneCalendar team for fixing this so quickly! :)

Same issue for MS 365 calendar (but not google calendar) on iOS. Started 3/08. Error message "Nullable object must have a value."

I god the same issue a few days ago with my microsoft acount calendar sync issue. How to solve it?

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