Unable to mount/access phone after upgrade to Ubuntu 14.04

A Nokia Lumia 920 will not mount in 14.04. When I was running 13.10 this wasn't an issue. What should I try? Or will I have to revert to 13.10?

What mtp-detect shows:

kjhg@kjhg-LIFEBOOK-AH530-HD6:~$ mtp-detect
Unable to open ~/.mtpz-data for reading, MTPZ disabled.libmtp version: 1.1.6

Listing raw device(s)
Device 0 (VID=0421 and PID=0661) is a Nokia Nokia Lumia WP8.
   Found 1 device(s):
   Nokia: Nokia Lumia WP8 (0421:0661) @ bus 2, dev 4
Attempting to connect device(s)
PTP_ERROR_IO: failed to open session, trying again after resetting USB interface
LIBMTP libusb: Attempt to reset device
LIBMTP PANIC: failed to open session on second attempt
Unable to open raw device 0
OK.

Solution 1:

Problems like this happen a lot during an upgrade. I recommend that you simply install 14.04 over your existing setup. You'll want to backup your /home directory but most installs will save that. The reason this happens IMHO is when the config files are updating they don't always update correctly. I've actually seen Linuxes where this is a listed "upgrade method".

Solution 2:

Installing mtp-tools and/or mtpfs has solved my problem:

sudo apt-get install mtp-tools mtpfs

You may need to reboot to get it work completely.