I'm a ninja

Fatal error: Uncaught yii\web\HeadersAlreadySentException: Headers already sent in /srv/http/beggerplate/www/vendor/yiisoft/yii2/web/Response.php on line 414. in /srv/http/beggerplate/www/vendor/yiisoft/yii2/web/Response.php:366 Stack trace: #0 /srv/http/beggerplate/www/vendor/yiisoft/yii2/web/Response.php(339): yii\web\Response->sendHeaders() #1 /srv/http/beggerplate/www/vendor/yiisoft/yii2/web/ErrorHandler.php(135): yii\web\Response->send() #2 /srv/http/beggerplate/www/vendor/yiisoft/yii2/base/ErrorHandler.php(262): yii\web\ErrorHandler->renderException() #3 [internal function]: yii\base\ErrorHandler->handleFatalError() #4 {main} thrown in /srv/http/beggerplate/www/vendor/yiisoft/yii2/web/Response.php on line 366