system installation - Firefox, Thunderbird will not open after attempting upgrade 14.04-14.10

Before I tried to upgrade from Ubuntu 14.04 to 14.10, both Firefox and Thunderbird worked properly. I tried to upgrade, but it hung somehow and I had to reboot, (press the reset button, the little one beside the big start button.) It tried to boot into 14.10, but hung after accepting the password. Using an Ubuntu 14.04 LiveCD, I recovered my /home directory to an external HD, then re-installed 14.04 and copied my saved /home directory back to the new /home directory like this:

sudo cp -dRv dev/sdb1/home/* home/ 

sudo was necessary as cp otherwise could not read all of the files

Since then, neither Firefox nor Thunderbird will run.

• When I click on Firefox in the launcher, it returns, "Your Firefox profile cannot be loaded. It may be missing or inaccessible." The load mouse pointer continues "spinning" for a minute or so, then just returns to a standard pointer. Firefox never opens a window.




• When I click on Thunderbird in the launcher, it returns, "Thunderbird is already running, but is not responding. To open a new window, you must first close the existing Thunderbird process, or restart your system." The load mouse pointer continues "spinning" for a minute or so, then just returns to a standard pointer. Thunderbird never opens a window.

All other software seems to work properly.

I've checked and the old .mozilla and .thunderbird directories were copied over along with my other files. I've tried changing permissions in both directories and the files in them; no joy. I've tried renaming the .mozilla directory; Firefox creates a new one, but behaves the same way. I recovered my old /etc, /var and /usr directories along with my old /home directory; copying the old /etc directory to the new one did nothing, the old /var directory crashed the system. I tried upgrading to 14.10; Unity seems a little slower, Firefox and Thunderbird behave the same way. I've tried un-installing and re-installing Firefox and Thunderbird using Ubuntu Software Centre; no joy.

For now I'm using Chromuim and reading emails online. This is will do for now, but is sub-optimal. I would be grateful for any help.

UPDATE -- I made a guest account. Firefox and Thunderbird work correctly in that.