Event ID 641 — Trust Policy and Configuration

Applies To: Windows Server 2008 R2

The Active Directory Federation Services (AD FS) trust policy file defines the set of parameters that a Federation Service requires to identify partners, certificates, account stores, claims, and the various properties of these entities that are associated with the Federation Service.

Event Details

Product: Windows Operating System
ID: 641
Source: Microsoft-Windows-ADFS
Version: 6.1
Symbolic Name: EmailSuffixInvalid
Message: The Federation Service encountered an error while loading the trust policy. A configured e-mail suffix contains the @ sign.

If this error occurs during startup of the Federation Service, the Federation Service will be not be able to start, and all requests to the Federation Service will fail until the configuration is corrected. If this error occurs while the Federation Service is running, the Federation Service will continue to use the last trust policy that was loaded successfully.

User Action
This error should occur only if the trust policy file has been modified without use of the AD FS administrative tools. Remove the @ sign from the configured e-mail suffix.


Provide a valid e-mail suffix

This error occurs only if the trust policy file has been modified without the use of the Active Directory Federation Services snap-in.

To perform this procedure, you must be a member of the local Administrators group, or you must have been delegated the appropriate authority.

Remove the @ sign for the configured e-mail suffix from the trust policy file. Provide a valid e-mail suffix:

  1. In Notepad or another text editor, open the TrustPolicy.xml file that, by default, is in %systemdrive%\windows\systemdata\adfs.
  2. In the emailsuffixvalidationtransform section, delete the @ sign that is specified in the allowedsuffix section.


Verify that you can access the Active Directory Federation Services (AD FS)-enabled application from a client browser and that the resource can be accessed.

Trust Policy and Configuration

Active Directory Federation Services