Failed to assign SPN on account 'CN=.…', error 0x21c7/847 → The operation failed /modification is not unique forest-wide

Updated August 20, 2024 19:04

Debbie Redmond

This message appears when you run the setspn -S command.

Cause

This error appears for one of the following reasons:

The SPN already exists and is associated with a different user.
The account that is running the SPN command does not have permission to create an SPN.

Perform the following actions:

Type the following command to determine if the SPN exists: setspn -Q HTTP/%computername%.
- If an SPN is found, the output displays the details about the SPN.
- If an SPN is not found, the output displays the message No Such SPN found.
If an SPN is found, type the following command to delete the existing SPN: setspn -d HTTP/%computername% associated_user, and the create the SPN.
If an SPN is not found, contact your Active Directory team to create the required SPNs.