我正在使用Laravel构建一个项目。在localhost上运行正常，但是当我将其上载到服务器（服务器已安装comodo ssl）时，出现以下错误：

RuntimeException in EncryptionServiceProvider.php line 29:
No supported encrypter found. The cipher and / or key length are invalid
in EncryptionServiceProvider.php line 29
at EncryptionServiceProvider->Illuminate\Encryption\{closure}(object(Application), array()) in Container.php line 733
at Container->build(object(Closure), array()) in Container.php line 626
at Container->make('encrypter', array()) in Application.php line 674
at Application->make('Illuminate\Contracts\Encryption\Encrypter') in Container.php line 837
at Container->resolveClass(object(ReflectionParameter)) in Container.php line 800
at Container->getDependencies(array(object(ReflectionParameter)), array()) in Container.php line 771
at Container->build('SahraSalon\Http\Middleware\EncryptCookies', array()) in Container.php line 626
at Container->make('SahraSalon\Http\Middleware\EncryptCookies', array()) in Application.php line 674
at Application->make('SahraSalon\Http\Middleware\EncryptCookies') in Pipeline.php line 123
at Pipeline->Illuminate\Pipeline\{closure}(object(Request)) in CheckForMaintenanceMode.php line 42
at CheckForMaintenanceMode->handle(object(Request), object(Closure))
at call_user_func_array(array(object(CheckForMaintenanceMode), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 124
at Pipeline->Illuminate\Pipeline\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 103
at Pipeline->then(object(Closure)) in Kernel.php line 118
at Kernel->sendRequestThroughRouter(object(Request)) in Kernel.php line 86
at Kernel->handle(object(Request)) in index.php line 54

谁能帮助解决此错误？