ERROR_SERVER_SID_MISMATCH - 628 (0x274)
The server process is running under a SID different than that required by client.
Updated: Feb 21, 2026
Technical Meaning
The error code ERROR_SERVER_SID_MISMATCH with the numeric value 628 and hexadecimal representation 0x274 indicates that a security identifier (SID) mismatch has occurred between the client and server processes. This typically arises in scenarios where a client process expects a specific SID for authentication or authorization, but encounters a different one during communication.
Error Details
When this error is encountered, it suggests that there is an inconsistency in the SIDs used by the client and server. SIDs are unique identifiers assigned to entities such as users and groups within a security context. In a client-server interaction, both parties must agree on the expected SIDs for proper authentication and authorization.
Usage Context
This error can occur in various contexts where client-server communication is involved, particularly in scenarios requiring secure authentication or access control. Common examples include network services, remote procedure calls (RPC), and distributed applications that rely on consistent security contexts across processes.
Developer Interpretation
Developers should interpret this error as a sign of misconfiguration or an issue with the security context setup. The client process may be expecting a specific SID for authentication purposes, but the server is operating under a different one. This can lead to failed authentication attempts and restricted access to resources.
Common Causes
- Incorrect configuration of SIDs on either the client or server side.
- Mismatched security contexts between the client and server processes.
- Misconfigured security policies or group memberships.
- Inconsistent domain or local user configurations across networked systems.
Related Errors
ERROR_ACCESS_DENIED(5)ERROR_LOGON_FAILURE(1326)ERROR_INVALID_PARAMETER(87)
FAQ
Q: What does the error ERROR_SERVER_SID_MISMATCH mean?
A: It indicates a mismatch in SIDs between the client and server processes, leading to authentication or authorization issues.
Q: How can I resolve this issue?
A: Ensure that both the client and server are configured with matching SIDs for security contexts. Verify the security policies and group memberships on both sides.
Summary
The ERROR_SERVER_SID_MISMATCH error highlights a critical issue in client-server communication where the expected SID does not match the actual one used by the server. Developers should focus on ensuring consistent security configurations across all processes involved to prevent such errors.