How to fix Error 8774 on Windows Server 2025 / Windows 11

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Why This Error Happens

Error 8774 in SQL Server 2025 typically occurs when the Database Engine fails to retrieve data from a linked server, external data source, or PolyBase connection due to a broken authentication chain or expired credential mapping. This is commonly triggered by Kerberos delegation failures, mismatched SQL Server service account permissions, or corrupted connection metadata in the sys.servers catalog. In Windows Server 2025 environments, Group Managed Service Account (gMSA) token refresh issues are also a frequent root cause, especially after a password rotation cycle.

Step-by-Step Resolution Guide

Step 1: Verify Linked Server and Credential Configuration

  • Open SQL Server Management Studio (SSMS) and expand Server Objects > Linked Servers.
  • Right-click the linked server reporting the “Getting Data” failure and select Properties > Security.
  • Confirm the mapping uses a valid login with “Be made using this security context” and re-enter the password to force a credential refresh.

Step 2: Check Service Account and Kerberos Delegation

  • Open Active Directory Users and Computers on the Windows Server 2025 domain controller.
  • Locate the SQL Server service account (or gMSA) and confirm “Trust this computer for delegation to specified services only” is enabled under the Delegation tab.
  • Run klist from an elevated Command Prompt on the SQL Server host to confirm a valid Kerberos ticket exists for the target data source.

Step 3: Repair Corrupted Linked Server Metadata

  • In SSMS, run the following to drop and recreate the broken linked server entry:
EXEC sp_dropserver 'LinkedServerName', 'droplogins';
EXEC sp_addlinkedserver 'LinkedServerName', 'SQLNCLI';
EXEC sp_addlinkedsrvlogin 'LinkedServerName', 'false', NULL, 'RemoteUser', 'RemotePassword';
  • Restart the SQL Server (MSSQLSERVER) service via services.msc to clear cached connection handles.

Step 4: Validate Firewall and Port Accessibility

  • On Windows Server 2025, open Windows Defender Firewall with Advanced Security.
  • Confirm inbound/outbound rules allow TCP port 1433 (or the custom port configured) between the SQL Server instance and the remote data source.
  • Use Test-NetConnection -ComputerName RemoteServer -Port 1433 in PowerShell to confirm connectivity.

Alternative or Verification Steps

  • Run SELECT * FROM OPENQUERY(LinkedServerName, 'SELECT 1') in SSMS to confirm the “Getting Data” operation completes without triggering Error 8774.
  • If the issue persists, temporarily switch the linked server authentication to a SQL login (instead of Windows Authentication) to isolate whether the fault lies in Kerberos delegation or the data source itself.