Issue with group calendars deleting entries (past and futur)

Occasional Contributor


We use an Office 365 group to manage meeting with our clients. Today, I've noticed that all past and futur calendar events were no longer in the calendar.

Any idea of what happened?

Meeting requests still visible in the conversation tab and if I click on a meeting request and ask to show this meeting in the calendar, it goes to the calendar select the time scheduled but there is no entry.

There is no auto archive option selected.

How can I put all the entries back in the calendar?
Please can you advise?

Many thanks for your help!

13 Replies
Hi Delphine,
Could you provide us with more details so we can debug this issue?
- Which Outlook client are you seeing this issue? Outlook on the Web? Outlook 2016? On all clients?
- Are past and future events for all groups missing?
Thank you

Hi Maria,

We are using Outlook 2016. 

We have only 1 group and all meetings, past and futur, have disappeared.
It happens every month.

I've first thought about an auto archive but it's not applied.

Thanks for your help!



Thank you, Delphine. Have you tried to going to Outlook on the Web and see whether meeting s are shown there? Could you try filing a ticket (Help > Contact Us > Talk to an Agent)?


Yes I've check on the Web version and the problem is excatly the same.


Hi Delphine, 

There's a known issue where when group owner deletes meetings from the group calendar, meeting requests are still shown in the conversation tab with no indication that these got deleted. I'm wondering if your issue is affected by this one. Are you the group owner? 


Hi Maria,

I'm the owner of this group and I didn't delete any meeting.

They just disappeared without any action from me.

This happened twice, so we have decided to go back to the basic shared calendar.

Which means that now members of this shared calendar do not receive anymore notifications but we need them.


@Delphine Demanet I've seen this same issue posted many places and we have had this happen to our group OOO calendar several times. You are not alone in this problem. We've called support a few times and haven't been able to recover the lost past/future events or get it to stop happening. It happend again this week which has encouraged us to look at other calendaring options but I don't cherish a platform change, so if you get anywhere with this o365 issue, I would love to hear about it from you!

@Gary Samson @Delphine Demanet Did you ever get to the bottom of this issue? We're seeing one of our group calendars remove all entries on a weekly basis, which is extremely frustrating!

@Chris Pike, I'll reach out to you via private message so I can gather necessary info from you and pass them to our engineering team who can further investigate this issue. 


@Chris Pike - Unfortunately, no. My IT person has called MS support several times over the last couple months but group calendars remain unreliable in O365. Our resolution was to abandon O365 group calendars. 


@Gary Samson@Chris Pike, unfortunately no. 

I've received an email saying that the problem will be passed to the engineering team for further investigation and that's it ! No more information since then (July 2017)....very disappointing.

Our resolution was, as you, to abandon O365 group calendars.


Hi everyone!

Really sorry to hear that you have had issues like this. :(

I have to admit that I have not seen this pop up on support calls as of yet. Any of you who had (or still have) this problem - do you mind emailing me with some details?

- If you had a support ticket with us on this, please send me the ticket number

- the name / email of the group that has this problem / when you had the problem last

Please don't post the information in here, just email me directly; maybe with a subject of "Group calendar issues" or something. Email ninob AT microsoftDOTcom. I'll work with engineering directly to see what is going on here, and will likely get back to you with more questions. :)

Hi @Nino Bilic - There are other threads on this issue and I sought out other people discussing the problem both in and outside of MS forums. There is another thread on this issue in the MS forum at I also slogged through Stack Overflow and Experts-Exchange for users addressing similar concerns. 

We had an MS support ticket opened on this that got closed because we opened it Friday evening and didn't respond by Sunday night. We learned the lesson of not opening MS Support tickets on Friday the hard way. We opened another ticket that I've sent you the number to in email, as you requested. 

Good luck Nino, I hope you can get this figured out for people...