iPhone and iPad recovery stops with error 14
I experienced this (error 14) when updating my iPhone 6.  I backed up the phone and apps in iTunes while downloading the OS update to iTunes.  Then I chose the iTunes Update Now button.  It took 18 minutes to arrive at the error code 14.  My phone then disconnected from my computer and could not be SEEN by my computer until I plugged the USB cable into a different USB port and then plugged in the phone. I was only given a choice to quit or totally reset the phone.  I did a reset which resulted in a choice to have a new phone or to restore it.  The first and second restore attempts failed. I chose restore from the phone choices.

It worked when I used the restore button from iTunes instead of using the choice on the phone. There were approx. 10 apps that did not restore but as I write this the phone is downloading them from the apps store.  My contacts are complete, as are my pictures and other personal data.  Yuck!  Always back up your phone before OS Updates!!!