Error or prompts for credentials in Outlook when Outlook Anywhere is disabled

In Microsoft Outlook, you may experience one or several of the following issues:

  • When you start Outlook in an existing profile, you receive the following error:

    Cannot start Microsoft Outlook. Cannot open the Outlook window.

    Error displayed when you start Outlook
  • When you start Outlook or create a new Outlook profile, you are repeatedly asked to enter credentials.

    Prompt for Credentials in Outlook
  • If you click Cancel at the credential prompt, you receive the following error message:

    The action cannot be completed. The connection to Microsoft Exchange is unavailable. Outlook must be online or connected to complete this action.

    Error displayed when you Cancel the credential prompt

This issue occurs because Outlook Anywhere is disabled in your protocol settings.
To fix this issue, run the following cmdlet in the Exchange Management Console.

Set-Casmailbox <mailbox> -Mapiblockoutlookrpchttp:$false
For more information about the Set-CASMailbox cmdlet, see the following Microsoft TechNet article: 
More information
You can verify that Outlook Anywhere is disabled by checking the protocol settings in ADSI Edit for the user:

protocolSettings in ADSI Edit

If there is a 1 following the fifth § character, as is shown in this screen shot, Outlook Anywhere is disabled.

If there is a 0 following the fifth § character, or if there is neither a 0 nor a 1, Outlook Anywhere is not disabled.

For more information about protocol settings and ADSI Edit, see the following TechNet article:

rpc over http rpc/http
Note This is a "FAST PUBLISH" article created directly from within the Microsoft support organization. The information contained herein is provided as-is in response to emerging issues. As a result of the speed in making it available, the materials may include typographical errors and may be revised at any time without notice. See Terms of Use for other considerations.

Article ID: 3120192 - Last Review: 12/02/2015 20:24:00 - Revision: 3.0

Outlook 2016, Microsoft Outlook 2013, Microsoft Outlook 2010

  • KB3120192