The nonce of the user operation is invalid. The user operation may be re-using an old nonce, or formatted the nonce incorrectly.

Solutions

1. Check that you are using the correct nonce for the user operation.
   1. Use the getNonce function to check the nonce, or call the getNonce function in the EntryPoint contract.
   2. Make sure that you are not using a nonce that is too far in the future (more than 10 higher than the current nonce).
   3. Verify that the nonce is formatted correctly.