| Previous | Next |
| RPC_E_INVALID_PARAMETER | RPC_E_SERVER_DIED_DNE |
RPC_E_CANTCALLOUT_AGAIN
Second outgoing call is not allowed on the same DDE channel
RPC_E_CANTCALLOUT_AGAIN is HRESULT 2147549201 (0x80010011) from winerror.h. The documented description is “There is no second outgoing call on same channel in DDE conversation.” The relevant context is the COM/RPC call control, message filtering, apartment routing, marshaling, security negotiation, or remote object lifetime.
What to verify
Verify that the active conversation, current outbound call, callback stack, and channel ownership are known. That boundary prevents this result from being misclassified as corruption, network failure, or a reason for an unsafe automatic retry.
Where it is encountered
- This result can be returned during cross-apartment or cross-process COM method invocation and activation.
- This result can be returned during STA message filtering, reentrancy, call cancellation, timeout, or retry handling.
- It can be returned during DCOM security initialization, proxy/stub marshaling, OBJREF processing, and server object lifetime.
The immediate focus is legacy OLE/DDE call control where code attempts a nested second outbound call on a channel already servicing one conversation.
Correct handling and recovery
Return from the current call before issuing another, queue the follow-up operation, and remove reentrant DDE or OLE automation from callbacks.
An unchanged retry loop can duplicate effects, deepen reentrancy, or hide an invalid lifetime transition.
Difference from nearby HRESULTs
It is channel-specific nested call prevention; RPC_E_CANTCALLOUT_ININPUTSYNCCALL concerns outgoing COM calls during input-synchronous dispatch.
Developer and administrator guidance
Document the component that returned the result so future occurrences can be correlated across client, proxy, server, package, and security logs.
Practical scenario
An OLE container receives a DDE callback and immediately issues another command on the same conversation. It queues the command until the first exchange completes.
References
Looking for a different code? Search another status or error code.