# AUR4109

## Error Message

`AUR4109: Invalid rule execution result.`

## Description

This error occurs when the validation system receives an invalid value from a rule execution (for example a non-boolean/non-result value).

## Common Scenarios

```ts
// ❌ Returning a string instead of a boolean/result
const badRule = () => 'yes' as any;
```

## Solution

* Ensure rule implementations return `true/false` (or the expected validation result object), or a `Promise` of that value.

## Troubleshooting

* Identify the rule that produced the invalid result and fix its return type.
* If you wrap/compose rules, ensure wrappers preserve the expected result type.