> ## Documentation Index
> Fetch the complete documentation index at: https://jiffyscan.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# AA33: Paymaster Validation Function Failure

> Troubleshooting validatePaymasterUserOp execution issues

<Note>
  Note: OOG = "Out Of Gas"
</Note>

The paymaster's `validatePaymasterUserOp` function encountered an issue:

* It may have reverted unexpectedly
* It may have exhausted its gas allocation

## Troubleshooting Steps

1. Gas Limit Check:
   * Increase the `verificationGasLimit` to cover `validatePaymasterUserOp` costs

2. For Custom Paymaster Contracts:
   * Review `validatePaymasterUserOp` implementation
   * Ensure proper signature verification logic (avoid reverting for invalid signatures)
   * For non-time-based signatures, return `uint(1)` for invalid signatures

3. For Third-Party Paymaster Services:
   * If using JiffyLabs and encountering issues, [contact their support](https://t.me/JiffyScan)

4. When Not Using a Paymaster:

   * Ensure the `paymasterAndData` field is not set:

   ```typescript theme={null}
   const opHash = await bundler.sendUserOp({
     paymasterAndData: "0x",
     // Additional operation details...
   })
   ```

5. Advanced Debugging:
   * Utilize tools like Tenderly for in-depth analysis