# Validation Error (Insufficient Fee Amount) during predicate call

**URL:** <https://forum.fuel.network/t/validation-error-insufficient-fee-amount-during-predicate-call/3058>\
**Category:** Rust SDK\
**Created:** [September 6, 2023, 9:20pm UTC](https://forum.fuel.network/t/validation-error-insufficient-fee-amount-during-predicate-call/3058 "2023-09-06T21:20:04Z")\
**Posts on this page:** 1\
**Showing post:** 6

<div class="post-metadata">

**Author:** ![segfault-magnet](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.fuel.network/segfault-magnet/32/3567_2.png) [@segfault-magnet](https://forum.fuel.network/u/segfault-magnet)\
**Post date:** [September 7, 2023, 6:39pm UTC](https://forum.fuel.network/t/validation-error-insufficient-fee-amount-during-predicate-call/3058/6 "2023-09-07T18:39:44Z")

</div>

@fuel We’re pretty sure this is a regression with fuels-rs v0.47.0. We’re working on confirming and solving the issue.

In the meantime, you can implement a workaround.

The issue is with our estimation mechanisms when using predicates – in order to circumvent it we have to have some gas present in inputs before we run `call()` on the `ScriptCallHandler`

A simple workaround for your case would be:

1. Change `init_wallets` so that each wallet gets more than 1 coin. Set it to at least 2:

```rust
pub async fn init_wallets() -> Vec<WalletUnlocked> {
    let config = WalletsConfig::new(Some(5), Some(2), Some(1_000_000_000));
    launch_custom_provider_and_get_wallets(config, None, None).await
}

```

1. Add enough base asset to inputs and add the change output:

```rust
// in `fulfill_order`
        let base_asset = wallet
            .get_asset_inputs_for_amount(BASE_ASSET_ID, 10)
            .await?;
        inputs.extend(base_asset);

        let change = Output::change(wallet.address().into(), 0, BASE_ASSET_ID);
        outputs.push(change);

        let script_call = ScriptCallHandler::new(
            vec![],
            UnresolvedBytes::default(),
            wallet.clone(),
            provider.clone(),
            Default::default(),
        )
        .with_inputs(inputs)
        .with_outputs(outputs)

```

Your test should now pass. We’ll work on a fix asap.

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