O365 calendar integration to 3rd party app calendly not working due to randomly changing calendar ID

Copper Contributor

We use calendly to schedule meetings with external parties. It was working great until late September 2021. Around this time O365 calendar disconnected regularly with the error calendar not found.


After troubleshooting with Calendly and Microsoft the answer received from Calendly support was:

"I reviewed the logs for your account again earlier today, and I now see some errors related to a known issue that some of our Office 365 users have reported (which is fundamentally caused by the calendar IDs returned from Microsoft are changing at random)."


Looking for help here. Calendar integration with O365 user pass was great while it was working. Other users in our tenant continue to work, this issue is specific to my user, the global admin user.


Current workaround is to use an outlook desktop sync app to calendly but the experience is significant downgrade.


Any recommendations to troubleshoot?



2 Replies

@fwdLarry Apparently this is still an issue. They told me they had contacted MS for a resolution but that's it. What were you using to make it consistent?

hi @sanorton,


Yes this is still an issue an pain point for us. I am not aware of a resolution make the calendar ID static and consistently connect to 3rd party apps like calendly. I tried other calendar scheduling apps like zcal and the same issue presents.


If you find a solution Id love to hear it!