RPC_S_PROTSEQ_NOT_SUPPORTED - 1703 (0x6A7)
The RPC protocol sequence is not supported.
Updated: Feb 21, 2026
Technical Meaning
The error code RPC_S_PROTSEQ_NOT_SUPPORTED (1703, 0x6A7) indicates that the system or service encountered a request for an unsupported Remote Procedure Call (RPC) protocol sequence. This means that the requested RPC protocol is not recognized or supported by the current configuration of the system.
Error Details
This error typically occurs when an application attempts to initiate an RPC call using a protocol sequence that is not available on the local machine or the remote server. The RPC protocol sequence defines the specific set of protocols and services required for communication between client and server applications.
Usage Context
The RPC_S_PROTSEQ_NOT_SUPPORTED error can arise in various scenarios, such as:
- Attempting to use a deprecated or unsupported RPC protocol sequence.
- Mismatch between the expected and actual RPC protocol sequences during inter-process communication.
- Configuration issues where the required RPC protocols are not properly installed or enabled on the system.
Developer Interpretation
Developers should interpret this error as an indication that the requested RPC protocol is not supported by the current environment. This could be due to missing components, incorrect configuration settings, or using a protocol sequence that has been deprecated or removed from the system.
Common Causes
- Incorrectly configured RPC service on the client or server side.
- Missing or outdated RPC protocol libraries.
- Using an unsupported or deprecated RPC protocol sequence in the application code.
Related Errors
RPC_S_SERVER_UNAVAILABLE(1728, 0x6C0): The remote server is not available for processing the request.RPC_S_INVALID_BINDING(1719, 0x6B3): The binding handle used in an RPC call is invalid or has been freed.
FAQ
Q: What does the error code RPC_S_PROTSEQ_NOT_SUPPORTED mean?
A: This error indicates that the requested Remote Procedure Call protocol sequence is not supported by the system or service.
Q: How can I resolve this issue?
A: Ensure that all required RPC protocols are properly installed and configured. Verify that the application code uses a supported protocol sequence, and check for any deprecated or removed components.
Summary
The RPC_S_PROTSEQ_NOT_SUPPORTED error signifies an unsupported Remote Procedure Call protocol sequence in the system. Developers should focus on ensuring correct configuration and usage of supported RPC protocols to resolve this issue.