| Previous | Next |
| TAPI_E_NODEVICE | TAPI_E_NOTOWNER |
TAPI_E_NOREQUEST
No Assisted Telephony requests are pending
TAPI_E_NOREQUEST is HRESULT 2147745826 (0X80040022) from Tapi3err.h. AllStat describes it as “No Assisted Telephony requests are pending.” The result normally appears while retrieving or processing a queued request when no request is pending. Its useful interpretation is precise: the Assisted Telephony request is not valid for the exact provider, object, method, or lifecycle state that consumed it.
Typical call path
- This result belongs to TAPI 3 address, call-control, phone, terminal, media-provider, request, or call-center processing.
- Associate this result with one concrete native method among ITTAPI, ITAddress, ITBasicCallControl, ITCallInfo, ITStream, ITTerminal, ITPhone, provider events, and Assisted Telephony.
- Before releasing objects after this result, retain provider identity, object generation, current state, requested transition, and the event sequence surrounding retrieving or processing a queued request when no request is pending.
When the application constructed the Assisted Telephony request, it usually calls for caller-side validation. When enumeration or an event supplied it, it more often points to stale lifetime, provider replacement, device removal, configuration drift, or cross-session reuse. The ownership distinction for this HRESULT prevents a broad repair from masking the real defect.
Root-cause hypotheses
- A wrapper can trigger it by converting an enumeration, identifier, duration, structure size, encoding, or ownership rule incorrectly.
- It can occur when the caller supplies a malformed, unsupported, stale, or out-of-scope Assisted Telephony request.
- It can also indicate that the Assisted Telephony request belonged to another address, call, device, provider generation, user session, or COM object.
- An asynchronous event can produce it when removal, disconnect, cancellation, reinitialization, or a state transition occurs after validation.
Choose among those branches only after comparing the failed Assisted Telephony request with live capabilities or objects obtained from the same provider generation. A well-formed value can still be invalid because its scope, owner, state, or lifetime no longer matches the operation.
Diagnostic record
- Record it, 0X80040022, the native method, operation ID, elapsed time, process and thread IDs, application build, architecture, and COM apartment.
- capture request mode, registration scope, application identity, queue depth, request recipient, and event ordering.
- Keep provider version, address/call/phone/terminal identities, current state, requested state, object generation, and the first lower-level error that preceded it.
- Redact telephone numbers, credentials, recordings, user-user data, and directory attributes from it telemetry while retaining lengths, types, hashes, ranges, capability flags, and opaque correlation identifiers.
A useful incident can answer whether the Assisted Telephony request came from configuration, enumeration, user input, cached state, or a provider callback. The result record should also show whether the operation succeeds with a newly enumerated object or freshly validated value.
Investigation order
- Capture it at the first native return and identify the exact method used for retrieving or processing a queued request when no request is pending.
- Enumerate current provider capabilities or objects and compare them with the Assisted Telephony request rejected by it.
- Validate the Assisted Telephony request without silently correcting it; check type, size, range, encoding, identifier scope, ownership, and lifetime as applicable.
- Reconstruct the event timeline before it to find removal, disconnect, cancellation, service restart, provider reinitialization, or another state transition.
- Reproduce it with one object and one operation, then vary only the suspected field or state while tracking partial output and side effects.
Recovery conditions
The evidence-based correction for this HRESULT is to treat an empty request queue as a state result, wait notification, and do not invent a request object. After it follows a provider, device, service, or configuration change, obtain a fresh object because an old interface or opaque identifier may remain invalid after recovery.
Retry it only after the recorded input, provider generation, resource availability, or object state has changed. User-visible handling of it should describe the actionable condition—invalid data, wrong state, missing resource, unavailable service, or policy refusal—rather than displaying only the HRESULT.
Failure example
For example, a request handler drains the queue after two notifications and receives an empty result on the second pass; it returns to waiting The application should log the failed Assisted Telephony request, provider and object generation, native method, and state-changing event, then verify recovery with a newly obtained object instead of reusing the instance that returned it.
Nearby constants
TAPI_E_NOTREGISTERED says the application cannot receive requests; it says the registered queue is currently empty Keep that distinction when building dashboards and exception mappings for this HRESULT; otherwise input defects, lifecycle races, capacity limits, service outages, and final call outcomes collapse into one misleading category.
Implementation guidance
Operational repair for this HRESULT should target only the component identified by evidence: the Telephony service, service provider, COM server, device, configuration record, application package, or remote system. Copying arbitrary DLLs or broadly deleting registration data can create additional failures without correcting the original Assisted Telephony request.
References
- Microsoft: TAPI_E constants — official Microsoft documentation used to interpret it.
- Microsoft: TAPI 3.1 Reference
- Microsoft: Telephony API interfaces
Looking for a different code? Search another status or error code.