Multitasking Apps may only use background services for their intended purposes

Your app declares support for audio in the UIBackgroundModes key in your Info.plist, but we were unable to play any audible content when the application was running in the background.

Next Steps

The audio key is intended for use by applications that provide audible content to the user while in the background, such as music player or streaming audio applications. Please revise your app to provide audible content to the user while the app is in the background or remove the "audio" setting from the UIBackgroundModes key.

问题原因：  UIBackgroundModes  plist里面设置了audio running in the background,可是在应用中却没有使用。

解决步骤：target  -->  Capabilities  -->  Background Modes  -->  取消 audio and airplay . OK.搞定。