| Previous | Next |
| CO_E_CLASS_DISABLED | CO_E_ASYNC_WORK_REJECTED |
CO_E_CLRNOTAVAILABLE
COM activation requires an unavailable CLR
CO_E_CLRNOTAVAILABLE is HRESULT 2147500072 (0x80004028) from winerror.h. The documented description is “The common language runtime is not available.” The value must be interpreted at managed COM components or mixed native/managed activation.
The Common Language Runtime required by the component is missing, disabled, incompatible, or failed to initialize. When this result crosses a language or process boundary, preserve its original numeric form before projections replace it with a broad exception class.
Where the result appears
- This result may surface in managed COM components or mixed native/managed activation.
Typical causes and interpretation
Common cause categories are: the required runtime is not installed; architecture mismatches; hosting policy forbids loading; runtime initialization failed earlier. Do not treat the cause list as a checklist of simultaneous failures; use traces and postconditions to select the matching branch.
Key distinction: the Common Language Runtime required by the component is missing, disabled, incompatible, or failed to initialize.
Correct handling and recovery
The appropriate recovery is to install or repair the supported runtime, align component architecture and activation configuration, and avoid loading an arbitrary CLR version. A retry policy needs a bounded attempt count, a state refresh step, and a rule for reconciling work that may already have completed.
Cleanup following it must be generation-aware: do not destroy shared state or outputs owned by an earlier successful operation.
Practical scenario
A legacy managed COM server requires.NET Framework in a minimal image; deployment installs the supported feature and reruns registration.
Coverage should include the exact failure, a corrected success case, and the closest related HRESULT so classification remains stable.
Difference from related HRESULTs
COR_E_* values may describe failures after the CLR loads; it means COM cannot obtain a usable CLR for activation.
Tests and telemetry should retain the producing component and operation so future wrappers do not flatten this result into an ambiguous generic exception.
References
Looking for a different code? Search another status or error code.