Please see the following scheduled Microsoft change:
Date: Between May and late July 2026 (An exact implementation date is unavailable for WSU’s Microsoft environment.)
The following work is being completed: Microsoft is automatically upgrading shared Outlook calendars in Exchange Online from the legacy MAPI model to the modern REST model. During the upgrade, Microsoft will create a new calendar folder in a hidden state, sync all data in the background, and then make the upgraded calendar visible.
All affected groups: Delegates and users who access shared calendars in Outlook; users who have Editor (or higher) permissions on shared calendars in user or shared mailboxes
All affected processes:
- In normal upgrade scenarios:
- No Outlook restart is required.
- No interruption to normal user workflows is expected.
- No re-sharing or permission resets will be required.
- No data loss is expected.
- Temporarily hidden shared calendars are expected during this server-side upgrade and do not indicate a failure.
- Events older than one year are excluded in this initial change window.
Duration of impact: This is a permanent, Microsoft-driven change.
Necessary follow-up steps: If WSU users report issues with shared calendars (e.g. duplicate calendar folders, missing meetings) during this change window, please escalate to ITS for assistance. Common troubleshooting steps such as deleting and re-adding shared calendars, deleting duplicate folders, or creating new Outlook profiles are not recommended for resolving issues related to this Microsoft upgrade.
Questions? Please contact Crimson Service Desk at crimsonservicedesk@wsu.edu.