What does Windows error code 4402 (ERROR_APP_DATA_CORRUPT) mean?

ERROR_APP_DATA_CORRUPT

Fast Cache data corrupt.

ERROR_APP_DATA_CORRUPT is Win32 error 4402 (0x1132) and belongs to Fast Cache data integrity.

Where the result appears

• Deserializing a Fast Cache entry.
• Checking cached state after an interrupted write.
• Reading cache data across an application upgrade.
• Validating protected or checksummed cached content.

Likely causes

• the entry is truncated or partially replaced.
• checksum, signature, or structural validation failed.
• old and new schema fields were mixed during upgrade.
• storage or memory corruption altered the cached bytes.

Troubleshooting steps

• Record exact entry bytes or a safe hash.
• Record expected and detected schema version.
• Record integrity-check result and parser location.
• Record write journal, crash, and storage events.
• Record authoritative source used to rebuild the entry.

What to verify

Verify whether the entry is truncated or partially replaced. Check exact entry bytes or a safe hash together with expected and detected schema version.

Handling, retry, and recovery

Quarantine or delete only the affected cache entry through the owning API, reload authoritative data, and use atomic writes to prevent another partial replacement.

Difference from nearby codes

CORRUPT is not a freshness decision: even a newly written entry is unusable when its structure or integrity is invalid.

Practical example

A process crashes between truncating and rewriting a cache file.

References

• Microsoft: System Error Codes (4000–5999) — reference for error 4402.
• Microsoft: Storage management — reference for error 4402.
• Microsoft: Troubleshoot data corruption and disk errors — reference for error 4402.