Php artisan make:mail error

php artisan make:mail WhateverName 

UnexpectedValueException

 Invalid route action: [].

 at C:\Program Files (x86)\Ampps\www\instaclone\vendor\laravel\framework\src\Illuminate\Routing\RouteAction.php:92
    88▕      */
    89▕     protected static function makeInvokable($action)
    90▕     {
    91▕         if (! method_exists($action, '__invoke')) {
 ➜  92▕             throw new UnexpectedValueException("Invalid route action: [{$action}].");
    93▕         }
    94▕
    95▕         return $action.'@__invoke';
    96▕     }

 1   C:\Program Files (x86)\Ampps\www\instaclone\vendor\laravel\framework\src\Illuminate\Routing\RouteAction.php:47
     Illuminate\Routing\RouteAction::makeInvokable("")

 2   C:\Program Files (x86)\Ampps\www\instaclone\vendor\laravel\framework\src\Illuminate\Routing\Route.php:183
     Illuminate\Routing\RouteAction::parse("/", ["", ""])