Try to start *Windows* in safe mode with networking enabled. - Win10 http://windows.microsoft.com/en-us/windows-10/change-startup-settings-in-windows-10#v1h=tab01 - Win8 http://windows.microsoft.com/en-US/windows-8/windows-startup-settings-including-safe-mode - Win7 http://windows.microsoft.com/en-US/windows7/Start-your-computer-in-safe-mode

Still in Windows safe mode, start Thunderbird in safe mode. - https://support.mozilla.org/en-US/kb/safe-mode

Does the problem go away?

I am using Windows 7, sorry. No, the problem does not go away. Opened Windows Safe Mode, then Thunderbird Safe Mode (1) then Thunderbird Safe Mode Add-ons Disabled (2). I don't think AVG had anything to do with it, the email was not set up to go through the program.

2 possibilities that I see: Windows Update caused problem or Thunderbird update caused it. I can open Message Write window find, access some things through it. I can open Address Book also. The main window crashes.

Any other suggestions?

Do you have a crash ID? https://support.mozilla.org/en-US/kb/mozilla-crash-reporter-tb#w_viewing-crash-reports

Here is one: Crash ID: bp-0fa034eb-2833-4185-bccf-0acd32151207

There is an existing bug for this type of crash, but unfortunately no solution yet. See https://bugzilla.mozilla.org/show_bug.cgi?id=1072151

If this didn't happen with 38.3.0 you may consider downgrading TB, and monitor the status of the bug.

You can download v38.3.0 from https://ftp.mozilla.org/pub/thunderbird/releases/38.3.0/win32/en-US/

Thank you for your prompt help. I need this for business. I shall downgrade. Thunderbird, Mozilla, have been consistently high quality & reliable for years, and I'm sure this too will be sorted out. If it continues to happen, I shall let you know. My question, sorry I don't know --- should I completely delete current Thuderbird before downloading new downgrade? Question2 - will all of my emails be erased if I must erased program first?

Just downloaded 38.3.0, but program is still destabilized, does not stop loading until crash ... here is the crash report Crash ID: bp-7a5d00f3-0cc8-45e0-9be7-fc34a2151208

This is the same type of crash.

Tried Beta Version, same.

Are you saying you already tried TB 42.0 beta 2? https://www.mozilla.org/en-US/thunderbird/channel/

In any case, make sure you do have a full backup of your profile. http://kb.mozillazine.org/Thunderbird_:_FAQs_:_Backing_Up_and_Restoring

Yes, I did download the current Beta Version, hoping it had fixed the problem. Same crash.

Ok, if I back it up then totally delete Thunderbird, then try a reinstall? of 38.3?

Used MozBackup for profile Deleted Thunderbird 38.3 Restarted computer Installed 38.3 crashed Crash ID: bp-7e4846e9-6e4d-4d54-b06e-370572151208

My question was about the beta. https://support.mozilla.org/en-US/questions/1097870#answer-815294

Edit: I missed your update wrt trying the beta. At this time there's nothing else I can suggest.

I have the same problem since installing Win-11 and have looked all over for a solution. Is there one being de veloped???

So it's not the Windows version. It's not AVG. It may have started with a bug in the new Thunderbird version 38.4.0, but reading the Support section, it seems to have happened before in other versions. Now that it happened, NO version works on my computer.

Is there a way to completely remove every trace of Thunderbird from a computer? I'm wondering if something installed perhaps incorrectly deep into Windows that is not altered with updates. Corrupted perhaps? Has anyone tried Windows Installer Cleanup?

Can you not pass this on to someone else, rather than leave it hanging? I would be willing to work with anyone, one-on-one to explore the roots, the core of Thunderbird, to uncover the corruption.

What do you mean "pass this off"? Christ1 should look at it???

Christ1: "At this time there's nothing else I can suggest."

I mean send this problem w/ documentation to someone who is able/interested in digging deeper to fix this bug.

Please note, people answering questions here are not developers but mostly volunteers helping other users. As said before, a bug exists for your crash. How and when that bug gets fixed is beyond my control.

Thank you Christ1. Is there a way to do a complete uninstall of Thunderbird, core and all, erase all traces, so I can do a clean install? Otherwise, I'm afraid this computer will never be able to be used for Thunderbird again.

This crash is an out of memory crash. However the cause is very unlikely to be in memory allocation. It is in something that causes repeated allocations of memory, memory that is not released.

Before trying any of this a backup of your profile is crucial. Human error being what it is. And off the cuff instructions sometime being to much cuff.

1. Close Thunderbird
2. In the search in the start Menu type %appdata% and press enter.
3. Drag the Thunderbird folder that appears in the windows explorter to a backup medium (USB stick perhaps)

Backup complete

The original poster here said they felt AVG was not at fault, and they might be right. It may be a case of a corrupt mail file. But under no circumstances consider anything else until you have tried operating system safe mode and then started Thunderbird in safe mode while the operating system is in safe mode. This should remove almost all possible memory resident security software (and malware by the way) giving a cleaner look at the issue

In a case like this, the next thing is to try starting Thunderbird in safe mode AND offline mode. This will see no attempts to update or collect mail and should be more stable for other things to be done.

So first left create a special desktop item to start Thunderbird from.

• Open windows explorer and navigate to the location.
• "C:\Program Files (x86)\Mozilla Thunderbird"
• locate the Thunderbird.exe program and right click it and select copy.
• Go to your desktop
• Right click the desktop and select paste shortcut.
• Right click the shortcut and select properties.
• Select the Shortcut tab.
• In Target there is says "C:\Program Files (x86)\Mozilla Thunderbird\thunderbird.exe" add -offline (Case is important here. Offline is not going to work for example)
• Click Ok to save changes in the shortcut
• Use the new shortcut to start Thunderbird.

Now in offline mode (you can normally click the blue icon in the bottom left corner of a running Thunderbird to change this state.)

• Press Alt+F and on the menu that appears select compact folders.
• Allow the compact to complete
• Check folders for any obviously missing mail (this is what the backup was for)
• Restart Thunderbird normally.

No good? Try a new profile (this is setting up from scratch like was asked here

Edit the newly created shortcut to use -ProfileManager instead of -offline (again case is important) start Thunderbird with the shortcut once you have changed the startup option. When the profile manger appears on screen use the new option to create a new profile. Note here that this is really for testing purposes, so I would recommend only adding an IMAP account so nothing is lost if the profile gets deleted later. I am still on trying to find out what causes the crash.

Thank you Matt. Last night I changed name on Profile, reopened Thunderbird as new program/blank profile, worked fine. Also did an Imap account, working fine. I will retry according to your steps to see if I can save any of the old because I had 5 email accounts, 3 POP, 2 Imap and all my contact info that I really don't want to do again.

It was good to learn the problem is in the profile, not somewhere deeper in Windows.

My only other question (I will try your plan) is :: what folder are all my contacts in, IF it is separate. While the main window memory-crashed, when main window closed I could still open both my address book and the write window, and use the menu links at the top.

I am assuming it's a random bug associated with a fresh download, just a quirk and difficult to find because it is random.

Will get back later after completing your process. Other work goes on. thanks.