What does Windows error code 1914 (RPC_S_INVALID_ASYNC_HANDLE) mean?

RPC_S_INVALID_ASYNC_HANDLE

An asynchronous RPC API rejected the state handle itself

RPC_S_INVALID_ASYNC_HANDLE means the supplied RPC_ASYNC_STATE is not a valid asynchronous-call handle. The structure may not have been initialized, its runtime-owned fields may have been modified, it may have gone out of scope, or it may already have reached a terminal lifecycle state incompatible with the API.

Initialize each state with RpcAsyncInitializeHandle, preserve its address and storage until final completion, and never modify Size, Signature, Lock, or StubInfo. Correlate cancel, status, and complete calls by the same state pointer. Copying the structure byte-for-byte creates a second invalid owner rather than another call handle.

What to inspect

• Log the state address, initialization result, and every API using it.
• Keep the structure alive until RpcAsyncCompleteCall reaches a final result.
• Do not overwrite runtime-owned members or reuse stack storage prematurely.

References

• Microsoft: initializing RPC_ASYNC_STATE
• Microsoft: RPC_ASYNC_STATE structure
• Microsoft: APIs that validate the async handle