> ## 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.

# AA23: ValidateUserOp Function Failure

> Troubleshooting validateUserOp execution issues

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

The smart account's `validateUserOp` 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 `validateUserOp` costs, if it is less.

2. Logic Verification:

   * Review `validateUserOp` implementation
   * Confirm the user operation's validity

3. For Non-Paymaster Scenarios:

   * Verify sufficient native tokens in the `sender` address:

   ```typescript theme={null}
   const neededFunds = calculateRequiredPrefund({ userOperation });
   const accountBalance = await client.getBalance({
     address: userOperation.sender,
   });
   if (accountBalance < neededFunds) {
     throw new Error("Insufficient funds in sender account");
   }
   ```

4. For Paymaster Usage: - Ensure paymasterAndData is properly set:

   ```typescript theme={null}
   const opHash = await bundler.sendUserOp({
       paymasterAndData: "0x3b912be0270b59143985cc5c6aab452d99e2b4bb0000000000000000000000000000000000000000000000000000000064c0957400000000000000000000000000000000000000000000000000000000000000007d99385d8ef0af67affbf9944df8c121e9d1f6aef8dd82a4aeb5db310c42d3dc5b51c9e0835d94c3b22564d3d94f0e1d14e37571e46651da8de567d128a361a01b",
       // Additional operation details...
   })
   ```

5. Signature Verification:
   * Ensure your implementation doesn't revert for invalid signatures
   * For non-time-sensitive operations, return `uint(1)` for invalid signatures

6. Advanced Debugging:
   * Utilize tools like [Tenderly](https://tenderly.co/) for in-depth analysis