Laravel 4.2白色屏幕

I've updated from Laravel 4.1 to Laravel 4.2.

    "require": {
    "laravel/framework": "4.2.3",
    "cartalyst/sentry": "2.1.*",
    "webpatser/laravel-uuid": "1.*"
},

Now only can see a white screen, no whoops errors at all. I read that laravel 4.2 doesn't show any more whoops errors. How can I see if an error is happening?

In the app.php it doesn't matter if I put 'debug' => true, or false. Same white screen appears.

I've followed this guide http://laravel.com/docs/4.2/upgrade, but it doesn't says anything about this.

Anyone knows why is this happening?

have you considered setting php up to show errors, error_reporting in the php.ini

you can also look in the apache logs to find out what caused the errors