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AcquireTokenSilent always returns "Failed to acquire token silently. Call method AcquireToken"

    Question

  • Hi,

    I have a system that makes use of the AuthenticationContext.AcquireTokenSilent method via the Microsoft Graph part of Azure.  When I call the method it throws and exception with the error message of "Failed to acquire token silently. Call method AcquireToken".

    The application has been running on another Azure account (one that we are unable to access to check the settings), so I am 99.9% sure that it is not a code issue.  I am pretty certain I either have missed some setup step in Azure, or I have some web.config setting that is incorrect.

    Any suggestions would be greatly appreciated.

    Thanks

    Thursday, March 30, 2017 8:43 AM

All replies

  • Greetings,

    AcquireTokenSilent tries to obtain a token without the use of any additional user input.  This process can fail if there is a authentication challenge sent back from STS.  Challenges can be issued for authentication if the AAD is setup to enforce multi-factor authentication or one of the anti fraud mechanism built into the AAD is triggered.  If either scenario is encounted, the AcquireTokenSilent method will not succeed.

    Vittorio Bertocci wrote a very good blog on this scenario some time back:
    http://www.cloudidentity.com/blog/2014/07/08/using-adal-net-to-authenticate-users-via-usernamepassword/

    ActuireToken on the other hand is designed to attempt to handle these challenges.

    Regards,
    MaxV (MSFT)

    Friday, March 31, 2017 3:52 PM
  • Hi Max, Thanks for your quick response. I am struggling to find the MFA area in the new portal and am unable to access the classic portal (it just keep saying I don't have any subscriptions). Would you be able to point me in the right direction? I am pretty new to Azure so forgive my ignorance. Cheers Carl
    Monday, April 3, 2017 10:00 AM