Please post a crash ID. https://support.mozilla.org/en-US/kb/mozilla-crash-reporter-tb#w_viewing-crash-reports

This is what I can find:

AbortMessage: [2862] ###!!! ABORT: Could not load UTC timezone, brace yourself and prepare for crash: file /builds/slave/tb-rel-c-esr38-m64_bld-0000000/build/calendar/base/backend/libical/calUtils.h, line 110 AdapterDeviceID: 0x a2e AdapterVendorID: 0x8086 Add-ons: %7Be2fda1a4-762b-4020-b5ad-a41df1933103%7D:4.0.5,%7B972ce4c6-7e08-4474-a285-3208198ce6fd%7D:38.5.0,en-gb%40flyingtophat.co.uk:1.19.6 BuildID: 20151221142744 CrashTime: 1451838591 EMCheckCompatibility: true EventLoopNestingLevel: 1 FramePoisonBase: 7ffffffff0dea000 FramePoisonSize: 4096 InstallTime: 1451830569 Notes: AdapterVendorID: 0x8086, AdapterDeviceID: 0x a2expcom_runtime_abort([2862] ###!!! ABORT: Could not load UTC timezone, brace yourself and prepare for crash: file /builds/slave/tb-rel-c-esr38-m64_bld-0000000/build/calendar/base/backend/libical/calUtils.h, line 110) ProductID: {3550f703-e582-4d05-9a08-453d09bdfdc6} ProductName: Thunderbird ReleaseChannel: release SecondsSinceLastCrash: 1298 StartupTime: 1451838589 Theme: classic/1.0 Throttleable: 1 Vendor: Version: 38.5.0 useragent_locale: en-US

This report also contains technical information about the state of the application when it crashed.

Please click the link from the previous post and follow the instructions.

Hi I'm sorry I should have explained better; I can no longer find any Thunderbird folder in my Library - I recently upgraded from Mavericks to el Capitan and since then have not been able to find the Thunderbird data anywhere. So no profile or crash data. (and you already know I cannot open thunderbird) So all I have managed to do is to copy the data above from the actual crash message - I guess this is useless?

I can no longer find any Thunderbird folder in my Library - I recently upgraded from Mavericks to el Capitan and since then have not been able to find the Thunderbird data anywhere.

I have no idea how Apple handles OS upgrades, and whether user data is retained. You may need to restore a backup of your data.

Thanks for taking the time to advise me. I discover that my latest backups have no sign of thunderbird - although Mac's time machine theoretically saves everything so you can easily replicate your computer through a backup. I guess I'll try Apple for this. One last question - if you have the time. Can you think of any reason that I am unable to reinstall Thunderbird - it's supposed to be compatible with el capitan? I'm really asking if there's something really obvious I'm missing here. Many thanks again for your trouble

When mixing up different problems in a single thread things start getting confusing. If you do have a problem installing Thunderbird I'd suggest you start a new thread. Provide as much information as possible.

Explain in detail

• what you're doing
• what happens
• what you expect to happen

Apologies; I'm new to this. Thanks for your time.