Knowledge

RPC_S_PROCNUM_OUT_OF_RANGE - 1745 (0x6D1)

The procedure number is out of range.

Updated: Feb 21, 2026

Introduction

The RPC_S_PROCNUM_OUT_OF_RANGE error code (1745, 0x6D1) indicates that a procedure number used in Remote Procedure Call (RPC) operations is outside the valid range. This documentation provides an interpretation of this error and its usage context.

Technical Meaning

This error code is returned by RPC APIs when an invalid procedure number is encountered during the execution of an RPC call. The procedure number is part of the message header used in RPC communications, which identifies the specific operation to be performed on the server side.

Error Details

The RPC_S_PROCNUM_OUT_OF_RANGE error signifies that the procedure number passed to the RPC API does not match any valid operations defined within the service's interface. This can occur due to incorrect usage or corruption in the client-side code, or it might indicate a mismatch between the client and server interfaces.

Usage Context

This error is typically encountered when using Windows APIs related to RPC services. It may be returned by functions such as RpcBindingCall or RpcAsyncBindingCall, which are used for making remote procedure calls over an established binding context.

Developer Interpretation

When this error occurs, it indicates that the client attempted to invoke a procedure number that is not recognized by the server. This could be due to several reasons such as incorrect parameter values, invalid object types, or exceeding limits on supported operations. Developers should ensure that all RPC calls are made with valid and correctly formatted procedure numbers.

Related Errors

  • RPC_S_INVALID_BINDING (1702, 0x6A2): Indicates an invalid binding context.
  • RPC_S_CALL_FAILED (1743, 0x6C3): General failure in the RPC call.

    FAQ

    Q: What does the RPC_S_PROCNUM_OUT_OF_RANGE error mean?

    A: It means that a procedure number used in an RPC operation is out of range and not recognized by the server.

    Q: How can I resolve this issue?

    A: Ensure that all parameters, including the procedure number, are correctly formatted and within valid ranges. Verify the client and server interfaces for any discrepancies.

    Summary

    The RPC_S_PROCNUM_OUT_OF_RANGE error code is a specific technical indicator used in Windows RPC APIs to signal an invalid procedure number during remote procedure calls. Developers should carefully validate all input parameters to avoid this error.