Article ID: 2816904 - View products that this article applies to.
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When you try to run the Hybrid Configuration Wizard to enable a hybrid configuration in Microsoft Office 365, you receive the following error message:
Hybrid Configuration Failed with error "execution failed: Configure Legacy Exchange Support"
This issue may occur for one of the following reasons.
Solution 1: Add the OU=EXTERNAL (FYDIBOHF25SPDLT) public folderAdd the OU=EXTERNAL (FYDIBOHF25SPDLT) public folder. To do this, follow these steps on the mail server:
Then, in the output, look for a folder that has the following Identity:
Get-PublicFolder "\NON_IPM_SUBTREE\SCHEDULE+ FREE BUSY" -recurse | fl identity
\NON_IPM_SUBTREE\SCHEDULE+ FREE BUSY\EX:/O=<OrganizationName>/OU=EXTERNAL (FYDIBOHF25SPDLT)
Solution 2: Mail-enable the Exchange admin accountNote You should always mail-enable Exchange admin accounts. If the Exchange admin account isn't mail-enabled, the Hybrid Configuration Wizard may fail during the Set-HybridConfiguration or Update-HybridConfiguration process, and you may receive the following error message:
ERROR:Updating hybrid configuration failed with error 'Subtask ValidateConfiguration execution failed: Configure Legacy Exchange Support” as a symptom of the Admin account not being mail enabled.
Solution 3: Use ADSI Edit to remove the empty Servers containerWarning This procedure requires ADSI Edit. Using ADSI Edit incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems that result from the incorrect use of ADSI Edit can be resolved. Use ADSI Edit at your own risk.
The External Schedule+ Free Busy folder is used in hybrid scenarios when Exchange Server 2003 or Microsoft Office Outlook 2003 is used on premises. This external folder is installed on the Exchange 2010 public folder server so that the server can do the following:
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