: Cannot modify header information - headers already sent by (output started at /home/aikidoh/edc/vendor/cakephp/cakephp/src/Error/Renderer/HtmlErrorRenderer.php:37) [in
Code
$datatabl .= '</table>';
header('Content-type: application/force-download; charset=UTF-8;');
header('Content-disposition:attachment; filename= export_participants_'. $course->edc_type->name .'.xls');
Cake\Error\ErrorTrap->handleError() [internal], line ??
/home/aikidoh/edc/src/Controller/EdcCoursesController.php /home/aikidoh/edc/src/Controller/EdcCoursesController.php, line 279
App\Controller\EdcCoursesController->exportparticipants() /home/aikidoh/edc/vendor/cakephp/cakephp/src/Controller/Controller.php, line 505
Cake\Controller\Controller->invokeAction() /home/aikidoh/edc/vendor/cakephp/cakephp/src/Controller/ControllerFactory.php, line 166
Cake\Controller\ControllerFactory->handle() /home/aikidoh/edc/vendor/cakephp/cakephp/src/Controller/ControllerFactory.php, line 141
Cake\Controller\ControllerFactory->invoke() /home/aikidoh/edc/vendor/cakephp/cakephp/src/Http/BaseApplication.php, line 362
Cake\Http\BaseApplication->handle() /home/aikidoh/edc/vendor/cakephp/cakephp/src/Http/Runner.php, line 86
Cake\Http\Runner->handle() /home/aikidoh/edc/vendor/cakephp/cakephp/src/Http/Middleware/CsrfProtectionMiddleware.php, line 159
Cake\Http\Middleware\CsrfProtectionMiddleware->process() /home/aikidoh/edc/vendor/cakephp/cakephp/src/Http/Runner.php, line 82
Cake\Http\Runner->handle() /home/aikidoh/edc/vendor/cakephp/cakephp/src/Http/Middleware/BodyParserMiddleware.php, line 157
Cake\Http\Middleware\BodyParserMiddleware->process() /home/aikidoh/edc/vendor/cakephp/cakephp/src/Http/Runner.php, line 82
Cake\Http\Runner->handle() /home/aikidoh/edc/vendor/cakephp/cakephp/src/Routing/Middleware/RoutingMiddleware.php, line 117
Cake\Routing\Middleware\RoutingMiddleware->process() /home/aikidoh/edc/vendor/cakephp/cakephp/src/Http/Runner.php, line 82
Cake\Http\Runner->handle() /home/aikidoh/edc/vendor/cakephp/cakephp/src/Routing/Middleware/AssetMiddleware.php, line 70
Cake\Routing\Middleware\AssetMiddleware->process() /home/aikidoh/edc/vendor/cakephp/cakephp/src/Http/Runner.php, line 82
Cake\Http\Runner->handle() /home/aikidoh/edc/vendor/cakephp/cakephp/src/Error/Middleware/ErrorHandlerMiddleware.php, line 115
Cake\Error\Middleware\ErrorHandlerMiddleware->process() /home/aikidoh/edc/vendor/cakephp/cakephp/src/Http/Runner.php, line 82
Cake\Http\Runner->handle() /home/aikidoh/edc/vendor/cakephp/debug_kit/src/Middleware/DebugKitMiddleware.php, line 60
DebugKit\Middleware\DebugKitMiddleware->process() /home/aikidoh/edc/vendor/cakephp/cakephp/src/Http/Runner.php, line 82
Cake\Http\Runner->handle() /home/aikidoh/edc/vendor/cakephp/cakephp/src/Http/Runner.php, line 60
Cake\Http\Runner->run() /home/aikidoh/edc/vendor/cakephp/cakephp/src/Http/Server.php, line 104
Cake\Http\Server->run() /home/aikidoh/edc/webroot/index.php, line 37
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