The red text on grey points to an incompatible add-on, probably Lightning or a calendar-related add-on. Launch in safe mode (hold Shift when you start) and see if there's any change. If so, delete add-ons, including Lightning, until you find the offender.

http://kb.mozillazine.org/Gray_bar_below_status_bar

Thank you for this

I did as you suggested and removed the Lightning add-on and a mailmerge one. I also removed a dictionary.

There are now no add-ons. Thunderbird still crashes immediately when opening.

Is there something else I can try?

Thanks again.

Does it crash in safe mode? If it doesn't, launch in safe mode, check 'Reset toolbars and controls' and click 'Make changes and restart'. Result?

It does not crash in safe mode.

When I check 'Reset toolbars and controls' and click 'Make changes and restart' it tries to run (the throbber spins), flashes briefly* but it doesn't launch.

As I mentioned in my first post Thunderbird always opens the profile fine the first time and I can see all my email and email accounts. From this state is there a way to export my calendar and email, do a fresh install recreating my accounts and import the data?

Note *It is difficult to observe as this computer is very fast so I just see it "flash briefly"

If you can open it the 'first time', open Help/Troubleshooting, Crash Reports, and post the last few crash URLs. They look like bp-.....

Create a new profile with Profile Manager. Export calendars from the old profile by selecting a calendar in the Calendar tab, Export from the context menu. Export and import local mail with ImportExportTools NG; import to Local Folders on the new profile. Copy abook.mab and history.mab, which are Personal Address Book and Collected Addresses.

The fact it doesn't crash in safe mode may be due to other factors, such as hardware acceleration.

Thank you. It's late now. I will try all this tomorrow.

Thanks again.

I am back up and running. Thank you for all your help.

I managed to export the Calendar as you said.

I wasn't able to use ImportExportTools NG as it requires a restart to function. While I could open Thunderbird first time on a clean install, I could not reopen it.

What I did in the end was create a temporary email account (T) on the server. Then I ran Thunderbird in safe mode and added this new account as IMAP. I copied all the mail from the original POP account (O) into the new IMAP account.

I then closed Thunderbird and used the profile manager to create a new profile. I opened the new profile and added both T and O accounts as IMAP. I copied all mail from T into O. (I will delete T later)

I imported the calendar I had exported. Finally I copied abook.mab and history.mab from the old to the new profile as you recommended.

All is well with the world again.

Thank you so much for you help.