What does HRESULT 0x87C51003 (UTC_E_AOT_NOT_RUNNING) mean?

UTC_E_AOT_NOT_RUNNING

Identify the owning component: always-on trace controller

The code UTC_E_AOT_NOT_RUNNING (0x87C51003) belongs to ETW trace-session control, inside the Universal Telemetry Client/DiagTrack workflow. Correlate this HRESULT with the exact request attempt that returned it. It identifies always-on trace controller and reports that an operation assumed that the configured always-on trace had an active ETW session, but no such session was running; it does not by itself prove that all Windows diagnostic data collection is unavailable.

Code-specific check: The defining condition is “The always-on-trace is not running”. Confirm that condition at the producing API before applying recovery intended for a neighboring result.

The Universal Telemetry Client controls ETW sessions on behalf of diagnostic scenarios. ETW sessions have controller-owned names, in-memory buffers, providers, logging modes and lifetimes; a status at this layer should be correlated with the actual session list rather than inferred from the presence of an ETL file.

What to capture before retrying

Prove the condition

1. Associate this result with one request, one scenario version and one service process ID.
2. Save AutoLogger configuration, service state, ETW session list, boot sequence and first UTC operational events and the first lower-level HRESULT if one exists.
3. Change no policy, provider set or destination except for this test: restart only the responsible service or boot-time trace configuration and verify whether the expected session appears.
4. Compare the produced artifacts and operational events, not only the top-level return value.

Nearby result: UTC_E_TRACERS_DONT_EXIST — means tracer objects were never initialized, not merely that the always-on session stopped.

Trace-session note

Use an ETW controller view to list session name, GUID, mode, buffers and enabled providers while this result is active. The presence of an ETL file from an earlier run is not proof that the required in-memory session currently exists or is owned by UTC.

Confirm the repair

Repair the AutoLogger or service startup path before retrying the dependent action; do not fabricate an ETL file.

Technical references

• Microsoft Open Specifications: Windows error-code registry — reference for ETW trace-session control while interpreting it.
• Microsoft: Universal Telemetry Client configuration diagnosis
• Microsoft: Event Tracing for Windows
• Microsoft: WPR and ETW sessions