# removeErrorHandler()

Unmounts the error handling function.

When using React, it’s necessary to unmount functions to remove them from the DOM and perform necessary cleanup.

## Sample

Used within a JavaScript app uploaded as a static resource and referenced by `lightning:container`, this example unmounts a message error handling function. In a React app, functions must be mounted to be part of the document-object model and rendered in the output.

```javascript
componentWillUnmount() {
  LCC.removeErrorHandler(this.onMessageError);
}
```

## Arguments

| Name                                   | Type     | Description                                                                      |
| -------------------------------------- | -------- | -------------------------------------------------------------------------------- |
| `handler: (errorMsg: string) => void)` | function | The function that handles error messages encountered in the messaging framework. |

## Response

None.