The paymaster contract address is specified in the first 20 bytes of paymasterAndData.
The paymaster’s validatePaymasterUserOp function has rejected the user operation’s signature.

​
Resolution Checklist

  1. For Custom Paymaster Contracts:
    • Verify correct signing of the user operation
    • Ensure proper encoding of the paymaster signature in paymasterAndData
    • Confirm correct computation of the custom operation hash
    • Review the signature verification logic in your paymaster
  2. For Third-Party Paymaster Services (e.g., JiffyLabs):
    • Avoid modifying user operation fields after paymaster signing (except signature)
    • If unmodified but still encountering errors, contact their support
  3. Advanced Troubleshooting:
    • Employ Tenderly or similar tools to investigate validatePaymasterUserOp behavior