| Previous | Next |
| VFW_E_NO_COLOR_KEY_SET | VFW_E_NOT_OVERLAY_CONNECTION |
TPC_E_UNKNOWN_PROPERTY
Meaning
Windows documents TPC_E_UNKNOWN_PROPERTY as “TabletPC inking error code. Unknown property specified”. In practical terms, it is returned when Tablet PC code receives a property identifier that is not recognized by the relevant ink, packet or recognition component.
Where the failure belongs
This result belongs to Tablet PC ink, stylus and recognition. Tablet PC APIs span device enumeration, RealTimeStylus packet queues, ink-object lifetime and recognizer-specific capabilities. The numerical facility does not identify which Tablet PC layer produced the result. The relevant condition is that Tablet PC code receives a property identifier that is not recognized by the relevant ink, packet or recognition component.
Diagnostic sequence
- Confirm that the observed path matches this condition: Tablet PC code receives a property identifier that is not recognized by the relevant ink, packet or recognition component.
Likely causes
- Possible cause 1: a GUID is misspelled or belongs to another property family.
- Possible cause 2: a custom property was not registered or carried with the ink data.
- Possible cause 3: the installed platform version does not know the requested property.
Evidence to collect
- Capture 1: property GUID, expected value type and owning interface.
- Capture 2: list of properties actually present or supported.
- Capture 3: serialized ink or packet schema version.
Correct handling and retry
- Corrective action 1: query supported properties before reading optional values.
- Corrective action 2: preserve custom-property registration and serialization metadata.
- Corrective action 3: treat unknown optional properties as extensibility rather than corrupting the entire object.
Retry guidance. Retry only after choosing a supported property or installing the component that defines it. When retrying, avoid replay stale strokes, reorder stylus packets or reuse an invalid recognizer context.
Practical scenario
A plug-in asks RealTimeStylus for a recognizer-only property GUID; enumerating packet properties first prevents it.
Developer and operational guidance
Difference from nearby HRESULTs
TPC_E_INVALID_PROPERTY often means a known property is unavailable or unsupported in a recognizer context; it means the identifier itself is unknown to the component.
Official Microsoft references
Looking for a different code? Search another status or error code.