Exchange Online users see hash marks instead of free/busy information of on-premises users

When users who have mailboxes in Exchange Online look up free/busy information of on-premises users, the free/busy requests fail. Instead of the expected availability information, users see hash marks (\\\\) in the Scheduling Assistant. This can occur if the following conditions are true:
  • You're running Exchange Server 2013 Cumulative Update 12 (CU12) in the on-premises environment.
  • OAuth authentication is set up in your hybrid configuration.
Note The Hybrid Configuration Wizard will configure your environment to use OAuth for free/busy sharing if your environment doesn't contain any Exchange servers earlier than Exchange Server 2013 when you run the wizard.
A change was made in Exchange Server 2013 CU12 that prevents the free/busy request from being authorized properly.
To work around this issue, disable OATH in the organization. To do this, follow these steps:
  1. Connect to Exchange Online PowerShell. For more info, see Connect to Exchange Online PowerShell.
  2. Run the following command:
    Get-IntraorganizationConnector |set-IntraorganizationConnector -enabled $false
Note Using this workaround enables free/busy to work using a legacy federation approach. However, it prevents cross-premises eDiscovery from working. For more information, see Using OAuth authentication to support eDiscovery in an Exchange hybrid deployment.
This is a known issue. This issue will be resolved in a future Cumulative Update for Exchange Server 2013.
Still need help? Go to Office 365 for business on Microsoft Community or the Exchange TechNet Forums.

Article ID: 3193485 - Last Review: 09/20/2016 00:36:00 - Revision: 2.0

Microsoft Exchange Online, Microsoft Exchange Server 2013 Enterprise, Microsoft Exchange Server 2013 Standard

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