Windows has a bug when it comes to the AppointmentStore API. Somehow the AppointmentManager gets into a bad state which fails to acknowledge new appointments, and fails to provide updated appointment information. This means when adding an appointment Ink Calendar has no way of getting that new appointment data back from Windows 10.
How does this affect you?
When adding appointments to Ink Calendar they will not refresh or show up even when restarting the app. Ideally this is the worst case, but in some cases this bug results in Ink Calendar crashing.
What is being done about this?
I have made a separate app to demonstrate the several bugs within the AppointmentManger API but Microsoft has failed to acknowledge these bugs. When submitting a crash report through the Feedback Hub when this issues was being demonstrated Microsoft dismissed the feedback and did not provide guidance or any updates.
A post has been made to the Microsoft Q&A website on how to best “refresh” the AppointmentManager to stop getting stale data, but no progress has been made there.
What will happen?
It is unclear if this bug will ever get the attention required to be fixed. In the mean time Ink Calendar should work and not crash, but will occasionally have old calendar data. I have experienced this bug on Windows 11 as well, so the fix is not on the horizon as far as I can tell. I will continue working to find a solution, but in the mean time feel free to reach out to Microsoft, file feedback, and let the company know how this bug is affecting you.
Thanks for sticking with Ink Calendar through this pain. And if you have a fix for this bug please reach out, support at inkcalendar dot com, comment below, or tweet at me TheJoeFin.
Joe
Ink Calendar and Journal 
Hi. I am unable to use the calendar anymore. It won’t accept new appointments. The calendar from Monday to Friday has been greyed out. There is an error message in red below the calendar. It states the following:
Windows 10 AppointmentStore API has entered an error state and the calendar cannot be refreshed.
How does this get resolved? I use this on a daily basis and I need to be able to use it ASAP. Thank you.
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Fred, I’m sorry to hear you’re having issues. Please email support at inkcalendar dot com to continue this conversation and possibly provide photos. Unfortunately Windows 10 and 11 calendar API has been broken by Microsoft and not repaired.
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Have any interm work-arounds been found, such as reinstallation, clearing cache data, repairing windows or otherwise restoring an older state of the calendar API?
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I have not found any reliable work arounds. Reinstalling can be time consuming to sync all the ink data again, so I don’t consider that a good option. I haven’t found any cache which can be cleared, if you have any ideas I am interested. Repairing Windows hasn’t been tried by me. Not sure exactly what you mean by restoring an older state of the API, there has only been one version available to developers, if Microsoft changed it behind the scenes there is no way to call the older one.
I am open to suggestions and if you find anything out please report back, I am invested in finding a solution.
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