Calendar Sharing Issue Hybrid Office 365 - Downloading Calendar Entries

Copper Contributor

We are a large organization with a hybrid configuration setup and in the process of migrating users to 365.  We are federated and use ADFS for true SSO.   For calendar sharing to work between local exchange user and EXO user,  a calendar sharing invite must be sent and accepted. We have had this set up for a while but recently got a call where this took place between an on premise user whose calendar has over 9200 entries.  She has been here for years.  She sent a calendar sharing invite to an EXO user and they accepted, the calendar displays in outlook like it should but the entries are taking forever to populate. 

 

If you go into list view, you can see it download around 2000 entries fairly quickly from years ago but then it just stops downloading them unless you click on the calendar (in list view) and it will download some more and then stop.  You can repeat that process and it will continue but only at this rate it would take many hours of doing this.  I have had Outlook sitting in this list view on her calendar since yesterday and its only at 3459 entries of 9200+.

 

Same results show in OWA as well.

 

We tried this on another user who had a ton of entries and same issue.  If we try on user with not too many entries, it downloads those no issue.

 

Fiddler traces show the refresh calendar call being made successfully every so often.  No errors.

 

Has anyone experienced this behavior before and know of any solution?  

 

 

4 Replies

Looks like some client limitation or limitation for the sync process... @Julia Foran might be able to help here.

I've reached out to Julia for possible recommendations, thank you
Hi Richard,

Sorry that I'm not much help here. I wonder if this same experience happens if you disable caching for shared calendars in the Outlook for Windows client?

I'm not an expert on how hybrid sharing works, but this sounds like a case where our escalation engineers for calendar would be great to help debug what's going on here. Please do PM me once your case is resolved so that I can learn what the resolution was :)

--Julia

Has this been resolved? Experiencing same issue in our environment with calendar sharing. Thanks.