问题
I am using xcode 6.1 and osx 10.10. when I am running the app in device, The alert message shows as "app installation failed" and "the packet is unknown".my app running in ios simulator bur not not running in the device (ipad 8.1).
回答1:
Try the following steps
1.Check for the certificate
2.Delete the existing app from the iPad
3.Clean the Project
4.Install the application again
来源：https://stackoverflow.com/questions/26858040/what-is-mean-app-installation-failed