What does HRESULT 0x8004023A (TPC_E_INVALID_DATA_FROM_RECOGNIZER) mean?

TPC_E_INVALID_DATA_FROM_RECOGNIZER

Meaning

Windows documents TPC_E_INVALID_DATA_FROM_RECOGNIZER as “TabletPC inking error code. A recognizer returned invalid data”. In practical terms, it is returned when a handwriting recognizer returns data that violates the Tablet PC recognition contract.

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 a handwriting recognizer returns data that violates the Tablet PC recognition contract.

Diagnostic sequence

1. Confirm that the observed path matches this condition: a handwriting recognizer returns data that violates the Tablet PC recognition contract.

Likely causes

• Possible cause 1: the recognizer produces malformed lattice, range or property data.
• Possible cause 2: a third-party recognizer version is incompatible with the platform.
• Possible cause 3: memory corruption or incorrect marshaling alters returned structures.

Evidence to collect

• Capture 1: recognizer identity, version, language and capability flags.
• Capture 2: sizes, counts and bounds of returned structures before application parsing.
• Capture 3: the smallest ink sample that reproduces the invalid output.

Correct handling and retry

• Corrective action 1: update, repair or remove the faulty recognizer.
• Corrective action 2: validate all recognizer output before use.
• Corrective action 3: isolate the failing recognizer and retain a minimal ink sample for the vendor.

Retry guidance. Retry with the same recognizer only if the failure was transient and no malformed output is reused; otherwise select another recognizer or skip recognition. When retrying, avoid replay stale strokes, reorder stylus packets or reuse an invalid recognizer context.

Practical scenario

A third-party recognizer returns a lattice count larger than its allocated array for one ink sample; validation catches the contract violation behind it.

Developer and operational guidance

Difference from nearby HRESULTs

TPC_E_RECOGNIZER_NOT_REGISTERED means no recognizer is available; it means one ran but returned unusable data.

Official Microsoft references

• Microsoft: generic COM error codes
• Microsoft: RecognizerContext
• Microsoft: RealTimeStylus classes and interfaces