Power BI Refresh Error:
FailedToImpersonateUserException

What does this error mean?

The on-premises gateway failed to impersonate the user during Kerberos SSO. Fix requires an SPN and constrained delegation in Active Directory.

Common causes

• 1The Service Principal Name (SPN) for the gateway service account is missing or incorrectly configured
• 2Constrained delegation is not set up in Active Directory for the gateway machine
• 3The gateway service account does not have 'Act as part of the operating system' or impersonation rights
• 4The UPN of the Power BI user does not map to a valid Active Directory account
• 5The target data source SPN is not included in the constrained delegation list

How to fix it

1. 1Set up a Service Principal Name (SPN) for the on-premises gateway service account using setspn
2. 2Configure constrained delegation in Active Directory: grant the gateway computer account delegation to the target SPN
3. 3Ensure the gateway service runs as a domain account (not Local System) with impersonation rights
4. 4Map the Power BI user's UPN to an Active Directory account in the gateway data source settings if they differ
5. 5Review the gateway logs for the specific user ID and verify that account exists in AD
6. 6Test SSO by refreshing a dataset and checking the gateway logs for the impersonation attempt

Other gateway errors