Unable to mount iPhone unhandled lockdown error
I get this error when plugging in my iPhone 3GS. What does it mean?
Here's what worked for me (from imobiledevice.org):
When your device is plugged in, close out the error. Then run
idevicepair unpair && idevicepair pair
Then unplug your device and plug it back in.
Also, if it worked in the first place, but then you reset the iPhone (used Erase all Content and Settings option in the Reset menu in Settings) and it stopped mounting, then the solution is to remove the ~/.config/libimobiledevice/ directory and then replug your iPhone.