How to change the base path for error pages triggered by a route?

You can do that here : https://github.com/laravel/laravel/blob/master/app/Exceptions/Handler.php#L45

Check if the route is prefixed by dashboard, admin or whatever you path is and display your custom view.

@RachidLaasri Thanks Rachid!

Had to overwrite another parent method to get it working.
But isn't this bad practice for when you need to update the Laravel framework?

Is there maybe a better/safer way of doing this?

private $view_errors_path = 'errors';

public function render($request, Exception $e)
{
    if ($e instanceof ModelNotFoundException) {
        $e = new NotFoundHttpException($e->getMessage(), $e);
    }

    if ($request->is('app/*'))
    {
        $this->view_errors_path = 'app.errors';
    }

    return parent::render($request, $e);
}

protected function renderHttpException(HttpException $e)
{
    $status = $e->getStatusCode();

    if (view()->exists("{$this->view_errors_path}.{$status}")) {
        return response()->view("{$this->view_errors_path}.{$status}", ['exception' => $e], $status);
    } else {
        return $this->convertExceptionToResponse($e);
    }
}

The only things that gets replaced when running composer update is the vendor folder, as long as you don't change something in there you are fine.

@RachidLaasri Right, I know that. But what if the overwritten method changes inside vendor?
Then my overwritten method could cause errors, right?

I think the only proper way of changing these paths is for Laravel to have them in a config file.
Where is the best place I can post suggestions for the Laravel framework?

Yeah, and that's normal, you always have to check if there is something you need to change when a new version comes about.

In your case, i believe you don't have to override that method at all. You can do something like this :

/**
 * Render an exception into an HTTP response.
 *
 * @param  \Illuminate\Http\Request  $request
 * @param  \Exception  $e
 * @return \Illuminate\Http\Response
 */
public function render($request, Exception $e)
{
    if ($e instanceof NotFoundHttpException) {
        if($request->is('app/*')) {
            return response()->view("app.errors.404");
        }
        return response()->view("errors.404");
    }

    return parent::render($request, $e);
}

Or even something like this would work:

/**
 * Render an exception into an HTTP response.
 *
 * @param  \Illuminate\Http\Request  $request
 * @param  \Exception  $e
 * @return \Illuminate\Http\Response
 */
public function render($request, Exception $e)
{
    if ($e instanceof NotFoundHttpException) {
        
        $view = $request->is('app/*') ? 'app.errors.404' : 'errors.404';
        
        return response()->view($view);
    }

    return parent::render($request, $e);
}