What does HRESULT 0x8004180C (CI_E_BUFFERTOOSMALL) mean?

CI_E_BUFFERTOOSMALL

The caller buffer is too small for helper output

CI_E_BUFFERTOOSMALL is HRESULT 0x8004180C. Windows documents it as “The buffer is too small.”

State represented by the HRESULT

This result belongs to copying variable-length content-indexing data into caller-provided storage. The requested result cannot fit in the supplied byte or character capacity.

Likely triggers

• At step 1, the caller assumes a fixed maximum
• At step 2, size units are confused between bytes and characters
• At step 3, the value grows between size query and retrieval
• At step 4, terminator/alignment space is omitted

Compare the failing case with a control that preserves supplied size and required size and changes only unit and element width; this prevents unrelated environment differences from dominating the test.

Data for diagnosis

• Supplied size and required size.
• Unit and element width.
• Property or operation being retrieved.
• First and second call timestamps.

Capture supplied size and required size before releasing objects, closing handles or reconnecting. Retain the raw HRESULT with unit and element width, component version, UTC timestamp and correlation ID.

Investigation order

1. Confirm the API sizing convention.
2. Use checked arithmetic for allocation.
3. Handle growth between probe and copy with a bounded loop.
4. Set a reasonable upper limit for corrupt or hostile data.

Preserve the component version and target identity, then alter only the condition described as the requested result cannot fit in the supplied byte or character capacity.

Correct response

Allocate the measured capacity and retry the specific retrieval operation. Do not confuse this with system memory exhaustion. Record whether copying variable-length content-indexing data into caller-provided storage produced any content, update or state transition before returning.

Retry only after a concrete change in supplied size and required size or unit and element width.

Scope of the signal

It does not imply that the property is uncached or too large for the catalog property store. Without the call boundary for copying variable-length content-indexing data into caller-provided storage, it also cannot identify which wrapper or configuration layer introduced the condition.

Related HRESULT values

WBREAK_E_BUFFER_TOO_SMALL is phrase-specific; CI_E_PROPERTY_TOOLARGE concerns cache policy rather than caller storage.

Developer and administrator actions

• Record supplied size and required size with the returned HRESULT.
• In telemetry, correlate unit and element width with the target and component generation.
• For regression coverage, force the documented condition: the requested result cannot fit in the supplied byte or character capacity.

Example in a pipeline

A property name is retrieved through a two-call API, but the wrapper passes character count as bytes. Unit-aware sizing fixes the failure.

Official Microsoft references

• Microsoft: content-indexing helper-function values — official contract information relevant to this HRESULT.
• Microsoft: Content-Indexing values
• Microsoft: HRESULT values
• Microsoft: Windows Search SQL syntax