无法启动会话，因为第 0 行的 " " 已发送标头。不适用

Question

我正试图在一个现有项目中使用一台新的(Windows 8)笔记本电脑，该项目在我以前的(Mac OS X)机器和它部署到的所有(Linux)服务器中运行良好。

我已经从git克隆，运行composer，应用程序/控制台运行良好，我已经正确设置了配置文件，创建了数据库，并检查了DB架构是否正常，清除了缓存等，就像我以前做过一千次一样。

但现在我遇到了一个从未遇到过的错误，我不知道这是否与更新的依赖关系有关，这些依赖关系可能不一定使用与以前完全相同的版本，或者只是我在Windows环境中有点新手：

[1] RuntimeException: Failed to start the session because headers have already been sent by "" at line 0.
at n/a
in C:UsersDavidSitesmy-projectappcachedevclasses.php line 103
at SymfonyComponentHttpFoundationSessionStorageNativeSessionStorage->start()
in C:UsersDavidSitesmy-projectappcachedevclasses.php line 183
at SymfonyComponentHttpFoundationSessionStorageNativeSessionStorage->getBag('attributes')
in C:UsersDavidSitesmy-projectappcachedevclasses.php line 475
at SymfonyComponentHttpFoundationSessionSession->has('_security.last_error')
in C:UsersDavidSitesmy-projectvendorfriendsofsymfonyuser-bundleFOSUserBundleControllerSecurityController.php line 28
at FOSUserBundleControllerSecurityController->loginAction(object(Request))
in  line 
at call_user_func_array(array(object(SecurityController), 'loginAction'), array(object(Request)))
in C:UsersDavidSitesmy-projectappbootstrap.php.cache line 2841
at SymfonyComponentHttpKernelHttpKernel->handleRaw(object(Request), '1')
in C:UsersDavidSitesmy-projectappbootstrap.php.cache line 2815
at SymfonyComponentHttpKernelHttpKernel->handle(object(Request), '1', true)
in C:UsersDavidSitesmy-projectappbootstrap.php.cache line 2944
at SymfonyComponentHttpKernelDependencyInjectionContainerAwareHttpKernel->handle(object(Request), '1', true)
in C:UsersDavidSitesmy-projectappbootstrap.php.cache line 2245
at SymfonyComponentHttpKernelKernel->handle(object(Request))
in C:UsersDavidSitesmy-projectwebapp_dev.php line 29

Answer 1

检查覆盖HttpKernel类的任何自定义类，例如Bundle类，是否没有发送来自boot()等方法之一的头或响应