XCODE警告
Showing All Messages :-1: The iOS Simulator deployment target is set to 6.0, but the range of supported deployment target versions for this platform is 8.0 to 12.0. (in target 'MJRefresh')
解决方案
如果你是使用cocoapods，则最好pod install一下，然后project clean，不然有可能会出现其他错误