• Start Windows in safe mode with networking enabled - https://support.microsoft.com/en-us/help/12376/windows-10-start-your-pc-in-safe-mode
• Still In Windows safe mode, start Thunderbird in Troubleshoot Mode - https://support.mozilla.org/en-US/kb/troubleshoot-mode-thunderbird

Does problem go away?

- If no, then cause is either: bug in Thunderbird, a setting, file or folder (something) in your Thunderbird profile, your mail provider. Please attach to the bug report or support topic a file created from Help | Troubleshooting | copy text to clipboard

- If yes, the problem is gone, then (still in Windows safe mode) ... start Thunderbird normally -- If problem is still gone, then cause is likely a program loaded during windows startup. Possibilities include: antivirus software (AV), virus/malware, background downloads such as Windows or other program updates, to name a few. For AV information see https://wiki.mozilla.org/Thunderbird:Testing:Antivirus_Related_Performance_Issues -- If problem came back, then cause is likely a Thunderbird add-on - eliminate them by disabling add-ons one at a time in Tools | add-ons | extensions and restart Thunderbird after disabling (if you have many add-ons, try disabling half of them at a time)

- If results are unclear ... possibilities include temporary conditions such as contention from other running programs, downloads related to windows update, ...

Please let us know your findings.

I started windows in safe mode with networking enabled, then TB in trouble shoot mode and while it was in troubleshoot mode it crashed. The crash reports also fail to be submitted so I am unable to provide any info including creating a file from Help/Troubleshooting copied to clipboard. I did receive TB updates this am . I restarted my computer. With all programs closed, I opened TB, TB downloaded but the message portion of my emails did not appear below the list of emails at the top. I tried to open a couple of them and got a blank open page, then TB crashed again and the crash report said it failed to send.

Today, Nov 8th, TB is now crashing upon opening and while downloading messages so that I get nothing more than a blank screen after it crashes. The crash reports tell me there was a problem sending them. I have restarted my computer, shut it down and then restarted it and opened TB mail client with all other programs closed, and TB crashes before the messages are downloaded completely. Don't know what to do further. Thanks, Ann

What disk drive is thunderbird installed on? And which drive for your data?

Everything is on my one C Drive, data and TB. I was unable this am to open TB at all. The crash reporter failed to submit also. Then I got a Microsoft update, it installed, the computer restarted, so with no programs open I opened TB which this time downloaded and everything looked good. The emails are there, I can only read them by scrolling from the bottom pane. I can delete them, but when I click to open them, they open to a blank page. The pull down menus appear as a narrow blank pulldown. I tried to take a screenshot, but the pulldown disappears when I click the mouse and then it crashes again. This time the green line on the crash report completed but the message said it did not complete.

Please download and install https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/b_em0XqDQu-BvFczXxUsLQ/runs/0/artifacts/public/build/install/sea/target.installer.exe, which is not yet released 128.4.3. It has several fixes.

Hi, I did the download and AVG scanned it and found it safe. One question before I install it. It won't delete or remove my TB address book will it? Or my TB folders?

data is separate from programs.

This has solved my problem. Thank you so much. Install went easily and AVG pronounced it safe. Works great now!

annk2021, Thanks for the great feedback!