Notice: Undefined index: HTTP_REFERER in /app/src/Middlewares/Language.php on line 21 Fatal error: Uncaught RuntimeException: Output has been emitted previously; cannot emit response in /app/vendor/zendframework/zend-diactoros/src/Response/SapiEmitterTrait.php:37 Stack trace: #0 /app/vendor/zendframework/zend-diactoros/src/Response/SapiEmitter.php(26): Zend\Diactoros\Response\SapiEmitter->assertNoPreviousOutput() #1 /app/vendor/zendframework/zend-expressive/src/Emitter/EmitterStack.php(43): Zend\Diactoros\Response\SapiEmitter->emit(Object(Zend\Diactoros\Response\RedirectResponse)) #2 /app/vendor/zendframework/zend-expressive/src/Application.php(520): Zend\Expressive\Emitter\EmitterStack->emit(Object(Zend\Diactoros\Response\RedirectResponse)) #3 /app/public/index.php(57): Zend\Expressive\Application->run() #4 {main} thrown in /app/vendor/zendframework/zend-diactoros/src/Response/SapiEmitterTrait.php on line 37