Fatal error: Uncaught yii\web\HeadersAlreadySentException: Headers already sent in /var/www/html/gespat40-pcm-test/vendor/yiisoft/yii2/web/Response.php on line 428. in /var/www/html/gespat40-pcm-test/vendor/yiisoft/yii2/web/Response.php:366 Stack trace: #0 /var/www/html/gespat40-pcm-test/vendor/yiisoft/yii2/web/Response.php(339): yii\web\Response->sendHeaders() #1 /var/www/html/gespat40-pcm-test/vendor/yiisoft/yii2/web/ErrorHandler.php(135): yii\web\Response->send() #2 /var/www/html/gespat40-pcm-test/vendor/yiisoft/yii2/base/ErrorHandler.php(262): yii\web\ErrorHandler->renderException(Object(yii\base\ErrorException)) #3 [internal function]: yii\base\ErrorHandler->handleFatalError() #4 {main} thrown in /var/www/html/gespat40-pcm-test/vendor/yiisoft/yii2/web/Response.php on line 366