Errors/Chain errors
UnableToRecoverPublicKey
Check the argument values against the operation schema
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.
Remediation
Check the argument values against the operation schema
The same explanation is available in the terminal: btcli explain UnableToRecoverPublicKey.