Sign Out with SAML results in error from Azure AD

Hi,

I have SAML configured in my control panel, which is working fine by the way--all users can sign in nicely.

The issue happens when a user attempts to sign out. The idP I am using is MS Azure AD, and I have all of the url's correctly matched according to the document: https://azure.microsoft.com/en-us/documentation/articles/active-directory-saas-zoho-mail-tutorial/

Error from azure signout endpoint:

Sorry, but we’re having trouble signing you in.

We received a bad request.

Additional technical information:

Correlation ID: d0f0b37b-79e8-4972-985d-688cadef2437

Timestamp: 2016-08-21 19:08:57Z

AADSTS75005: The request is not a valid Saml2 protocol message.

-Mike