Warning (2): Use of undefined constant CLIENT_ID - assumed 'CLIENT_ID' (this will throw an Error in a future version of PHP) [APP/Controller/AdminEmailController.php, line 30]
Code Context

        $client_id = CLIENT_ID;
App\Controller\AdminEmailController::edit() - APP/Controller/AdminEmailController.php, line 30
Cake\Controller\Controller::invokeAction() - CORE/src/Controller/Controller.php, line 537
Cake\Controller\ControllerFactory::handle() - CORE/src/Controller/ControllerFactory.php, line 140
Cake\Controller\ControllerFactory::invoke() - CORE/src/Controller/ControllerFactory.php, line 115
Cake\Http\BaseApplication::handle() - CORE/src/Http/BaseApplication.php, line 317
Cake\Http\Runner::handle() - CORE/src/Http/Runner.php, line 77
Cake\Http\Middleware\CsrfProtectionMiddleware::process() - CORE/src/Http/Middleware/CsrfProtectionMiddleware.php, line 164
Cake\Http\Runner::handle() - CORE/src/Http/Runner.php, line 73
Cake\Http\Middleware\BodyParserMiddleware::process() - CORE/src/Http/Middleware/BodyParserMiddleware.php, line 157
Cake\Http\Runner::handle() - CORE/src/Http/Runner.php, line 73
Cake\Routing\Middleware\RoutingMiddleware::process() - CORE/src/Routing/Middleware/RoutingMiddleware.php, line 161
Cake\Http\Runner::handle() - CORE/src/Http/Runner.php, line 73
Cake\Routing\Middleware\AssetMiddleware::process() - CORE/src/Routing/Middleware/AssetMiddleware.php, line 68
Cake\Http\Runner::handle() - CORE/src/Http/Runner.php, line 73
Cake\Error\Middleware\ErrorHandlerMiddleware::process() - CORE/src/Error/Middleware/ErrorHandlerMiddleware.php, line 126
Cake\Http\Runner::handle() - CORE/src/Http/Runner.php, line 73
Cake\Http\Runner::run() - CORE/src/Http/Runner.php, line 58