Known issues with Outlook Desktop Shared Calendar Improvements

When a delegate sends an update on a meeting that requires attachment changes, the recipients may not get some or all of the attachment changes.

In the delegate's Sync Issues folder, you'll see sync errors. Example:

17:23:26 Synchronizer Version 16.0.15313

17:23:26 Synchronizing Mailbox 'Delegate User'

17:23:26 Synchronizing local changes in folder 'Manager User'

17:23:27 Uploading to server 'https://outlook.office365.com/mapi/emsmdb/?xxxxxxxx-xx'

17:23:30 Error synchronizing folder

17:23:30                                 [0-320]

WORKAROUND:

Disable Shared Calendar Improvements. 

WORKAROUND:

The issue can be temporarily resolved by disabling the Turn On Shared Calendar Improvements feature. Once this feature is disabled, you will need to close and restart Outlook. If you continue seeing the issue you may need to remove/re-add the calendar. To confirm that the feature has been fully disabled, view the Calendar Properties. On the General tab, the Type should be Folder containing Calendar items (MAPI). If you see Folder containing Calendar items (REST)ensure the Turn On Shared Calendar Improvements checkbox is unchecked and remove/re-add the Calendar again. 

WORKAROUND:

The issue can be temporarily resolved by disabling the Turn On Shared Calendar Improvements feature. Once this feature is disabled, you will need to close and restart Outlook. If you continue seeing the issue you may need to remove/re-add the calendar. To confirm that the feature has been fully disabled, view the Calendar Properties. On the General tab, the Type should be Folder containing Calendar items (MAPI). If you see Folder containing Calendar items (REST)ensure the Turn On Shared Calendar Improvements checkbox is unchecked and remove/re-add the Calendar again. 

WORKAROUND:

The issue can be temporarily resolved by disabling the Turn On Shared Calendar Improvements feature. Once this feature is disabled, you will need to close and restart Outlook. If you continue seeing the issue you may need to remove/re-add the calendar. To confirm that the feature has been fully disabled, view the Calendar Properties. On the General tab, the Type should be Folder containing Calendar items (MAPI). If you see Folder containing Calendar items (REST)ensure the Turn On Shared Calendar Improvements checkbox is unchecked and remove/re-add the Calendar again.