Even if it isn’t the first time you plugged your device in some settings may have been reset, and you’ll need to respond to the prompt again.So check your device and see if the message has popped up. If you ever pressed “Don’t Trust” by accident, your device won’t show up in i Tunes…and the message won’t pop up again. This is stored in the “Location & Privacy” settings in i OS.
I have a used i Pod Classic 5th Generation (A1136) that was purchased for a parent as it is compatible with all their 40-pin gear.
One of the parents already has an identical model which was "working fine" (although hadn't been synced for over a year).
From there you will either need to re-enable the driver, update it manually, or restart the Apple Mobile Device Service.
You can use an i Phone or i Pad without ever touching i Tunes, but it isn’t always easy.
The problem appeared to be corrupted firmware returning a string to Pn P that was not recognized.