备份了数据库，并在新服务器导入了，用scp把原服务器的flarum文件夹推到新服务器上了，config.php里的url也改了，运行路径设置为public，打开时显示
Fatal error: Uncaught Laminas\HttpHandlerRunner\Exception\EmitterException: Output has been emitted previously; cannot emit response in /www/wwwroot/flarum/vendor/laminas/laminas-httphandlerrunner/src/Exception/EmitterException.php:24 Stack trace: #0 /www/wwwroot/flarum/vendor/laminas/laminas-httphandlerrunner/src/Emitter/SapiEmitterTrait.php(40): Laminas\HttpHandlerRunner\Exception\EmitterException::forOutputSent() #1 /www/wwwroot/flarum/vendor/laminas/laminas-httphandlerrunner/src/Emitter/SapiEmitter.php(27): Laminas\HttpHandlerRunner\Emitter\SapiEmitter->assertNoPreviousOutput() #2 /www/wwwroot/flarum/vendor/laminas/laminas-httphandlerrunner/src/RequestHandlerRunner.php(98): Laminas\HttpHandlerRunner\Emitter\SapiEmitter->emit() #3 /www/wwwroot/flarum/vendor/flarum/core/src/Http/Server.php(42): Laminas\HttpHandlerRunner\RequestHandlerRunner->run() #4 /www/wwwroot/flarum/public/index.php(26): Flarum\Http\Server->listen() #5 {main} thrown in /www/wwwroot/flarum/vendor/laminas/laminas-httphandlerrunner/src/Exception/EmitterException.php on line 24
求问这个是什么问题