RPC_S_UNKNOWN_AUTHN_TYPE - 1741 (0x6CD)
The authentication type is unknown.
Updated: Feb 21, 2026
Technical Meaning
The RPC_S_UNKNOWN_AUTHN_TYPE error code indicates that the system encountered an unknown authentication type during a Remote Procedure Call (RPC) operation. This error typically arises when the client or server cannot recognize the authentication mechanism being used.
Error Details
- Error Name: RPC_S_UNKNOWN_AUTHN_TYPE
- Numeric Code: 1741
- Hex Code: 0x6CD
- Short Description: The authentication type is unknown.
This error suggests that there might be a mismatch between the expected and actual authentication types, or that an unsupported authentication method was encountered. It can occur in various RPC scenarios where authentication is required for secure communication.
Usage Context
The RPC_S_UNKNOWN_AUTHN_TYPE error is relevant in contexts involving RPC operations where authentication is necessary. This includes networked applications, distributed systems, and services that rely on secure remote procedure calls.
Developer Interpretation
When encountering the RPC_S_UNKNOWN_AUTHN_TYPE error, developers should consider the following:
- Verify that both the client and server are configured to use compatible authentication types.
- Ensure that all necessary security protocols and mechanisms are correctly installed and enabled on both ends of the RPC communication.
- Check for any recent changes or updates that might have altered the expected authentication behavior.
Related Errors
RPC_S_INVALID_AUTH_IDENTITY: Indicates an invalid authentication identity was provided.RPC_S_BAD_NETWORK_NAME: Suggests a network name issue, which could affect authentication.RPC_S_SERVER_TOO_BUSY: Implies that the server is unable to process the request due to overload or other issues.
FAQ
Q: What does the RPC_S_UNKNOWN_AUTHN_TYPE error mean?
A: It indicates an unknown authentication type during an RPC operation, suggesting a mismatch between expected and actual authentication types.
Q: How can I resolve this issue?
A: Ensure that both client and server are configured with compatible authentication mechanisms. Verify all necessary security protocols are correctly installed and enabled.
Summary
The RPC_S_UNKNOWN_AUTHN_TYPE error code signifies an unknown authentication type during RPC operations, indicating a potential mismatch between the expected and actual authentication methods. Developers should ensure compatibility and correct configuration of security protocols to resolve this issue.