# UnableToRecoverPublicKey (/docs/errors/chain/UnableToRecoverPublicKey)

While associating an EVM key, the secp256k1 public key recovered from the supplied signature could not be parsed. Check that the signature was produced by signing the expected EIP-191 message (hotkey plus block hash) with the EVM private key.

Declared by the `SubtensorModule` 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 UnableToRecoverPublicKey`.