This error show up when I am submitting the app to the store.What I have done is I have re-create the watch kit after I found that my project doesn't need to have glance interface.I have remove the target and old file.It have no problem when I execute on the device.
Error ITMS-90455: "Invalid WatchKit App Bundle.The value '2.1' for MinimunOSVersion key in info.plist in bundle 'appname.watchkitapp'is not supported."