thank you for providing these crash ids. unfortunately those crashes appear to be caused by trusteer rapport which is running on your device and hooking into firefox - please check that you are fully updated there or temporarily disable/uninstall that software for the moment.

please also get in contact with trusteer's support which are usually very quick to respond and fix issues like this: https://trusteer.secure.force.com/PKB/articles/en_US/FAQ/browser-crashes

Thank you for replying so quickly. I have been running Trustee Rapport for years with no problem, and everything has been OK until today. Can you tell me how to check that it is up to date, please?

copied from their support section...

To check if Rapport has the latest security and software updates:
Open the Rapport Console: Click Start > All Programs > Trusteer Endpoint Protection > Trusteer Endpoint Protection Console.
In the Product Settings area, click More Settings.
On the Product Settings screen, click Check for updates now.
The update status appears at the bottom of the console.

So helpful, many thanks. It is up to date, so I have emailed Trusteer support with all the details. Have temporarily disabled TR, and have not had a crash for helf an hour - bliss!!

Update - have now heard from TR support, and have sent a long email with all the info they requested, plus an ID report. I had to switch TR on to send the ID report via their console - firefox crashed immediately!! TR now switched off again, and reply awaited. Will post again once reply received.

Final update - IBM TR support applied a configuration update - to my computer which has resolved the problem. I have been impressed with their service. Many thanks, Philip for analysing my crash IDs, diagnosing the cause in the first place and pointing me in the right direction. I never would have worked this out.

great, thanks for following up & glad to hear that your firefox is working reliable again!