InvalidEquivocationProof

The submitted GRANDPA equivocation proof does not demonstrate a real double-vote: the two votes may be identical, from different rounds or set ids, or badly signed. Verify the proof contains two distinct votes by the same authority in the same round and authority set.

Declared by the Grandpa pallet; it classifies to the semantic code invalid_argument.

Remediation

Check the argument values against the operation schema

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