# InvalidKeyOwnershipProof (/docs/errors/chain/InvalidKeyOwnershipProof)

The key ownership proof does not establish that the offending GRANDPA key belonged to the claimed validator at that session. Regenerate the proof via the `generate_key_ownership_proof` runtime API for the exact set id and authority id in the report.

Declared by the `Grandpa` pallet; it classifies to the semantic code [`invalid_argument`](/docs/errors/invalid-argument).

## Remediation [#remediation]

Check the argument values against the operation schema

The same explanation is available in the terminal: `btcli explain InvalidKeyOwnershipProof`.