In most cases, error 14 iTunes (also known as iPhone error 14) results from connection issues, which may be related to the USB cord or the computer itself. Not only a normally functioning computer is necessary, but also an original USB cord is a guarantee to a stable connection. Therefore, all we need to do is to ensure that the computer, the USB cord and the Apple device all connect smoothly. To do this, simply follow the 2 steps below:
1) Connect other functioning Apple devices with your computer and see if the error 14 notification pops up. If the error stops showing up, then it's the Apple device that needs to be fixed. If it happens again, there is a probability that your cable or your computer is not designed for Apple devices.
2) Next, use the same USB cable to connect other functioning Apple devices with other computers. If the error code 14 iTunes stops showing up, then it is possible that your computer is problematic. Otherwise, you will have to find a Made for Apple USB cable