.net项目启动报错 The following errors occurred while attempting to load the app. - No assembly found containing an OwinStartupAttribute

报错信息：
The following errors occurred while attempting to load the app.

• No assembly found containing an OwinStartupAttribute.
• No assembly found containing a Startup or [AssemblyName].Startup class.
  To disable OWIN startup discovery, add the appSetting owin:AutomaticAppStartup with a value of "false" in your web.config.
  To specify the OWIN startup Assembly, Class, or Method, add the appSetting owin:AppStartup with the fully qualified startup class or configuration method name in your web.config.

原因：App_Startup，有文件未包含

处理方式：包含未包含的文件，重新生成即可