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Profole record loss

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  • Last reply by Toad-Hall

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As of today I've updated my TB to recommended 78 version. After install, all my presets and add-ons disappear, what made my TB useless. Like an option, I tried to reinstall previous version to get back all my setting, however, it didn't work and asked me set all Mail profiles as new (full emails access been gone).

I reinstalled back TB 78 to just get back access to my emails (forget about previous version presets) and as a huge surprise - got same welcome window to setup Profile record as new.

Anyone can assist me to get back my access to emails I use to run via PB? Or data is completely lost?

Thank you in advance for assistance.

As of today I've updated my TB to recommended 78 version. After install, all my presets and add-ons disappear, what made my TB useless. Like an option, I tried to reinstall previous version to get back all my setting, however, it didn't work and asked me set all Mail profiles as new (full emails access been gone). I reinstalled back TB 78 to just get back access to my emails (forget about previous version presets) and as a huge surprise - got same welcome window to setup Profile record as new. Anyone can assist me to get back my access to emails I use to run via PB? Or data is completely lost? Thank you in advance for assistance.

Chosen solution

re :Like an option, I tried to reinstall previous version to get back all my setting, however, it didn't work Ever since version 68 there has been a dedicated profile per installation. https://support.mozilla.org/en-US/kb/dedicated-profile-thunderbird-installation

There is a particular set method to being able to go back to the last 68 version after updating to a 78 version. Because there even more chnages to the address book file format.

Need to set updates to ask, change the address book, uninstall, then download old and reinstall, but do not auto start. Then use command line to force a backwards compatibily allowance.

In the 78 version:

  • Menu app icon > Options > General
  • Scroll down to 'Updates' section
  • select 'check for updates, but let me choose whether to install them'


To add also those email addresses back follow below steps: In Thunderbird

  • Help >Troubleshooting Information.

Under Application Basics section about 8 down in list see 'Profile Folder'.

  • Click on 'Open Folder'

A new window opens showing the contents of your profile name folder.

  • Exit Thunderbird

In the profile name folder - you will find the old address book files with extension .mab.bak - those files (abook and history) you need to:

  • -rename them to .mab (so remove the .bak part) eg: 'abook.mab.bak' becomes 'abook.mab'
  • -rename abook.sqlite and history.sqlite by adding .bak to the name. eg: abook.sqlite.bak
  • Do same for any other address books you created.


Now uninstall Thunderbird program. You could just delete the Mozilla Thunderbird folder from here:

  • C:\ Program Files (x86)\Mozilla Thunderbird
  • then empty the computer 'Recycle Bin'

Then get download from here:

Run the downloaded .exe file to install. On the last step of the installation do NOT select to start TB because you will need to run a command to allow you to downgrade.

Windows OS:

  • In search type : Run
  • Select the 'Run' app
  • Type: thunderbird.exe -P --allow-downgrade

note there is a space before and after -P

  • click on OK

Profile Manager starts select the desired profile name click on 'Start Thunderbird'.

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Chosen Solution

re :Like an option, I tried to reinstall previous version to get back all my setting, however, it didn't work Ever since version 68 there has been a dedicated profile per installation. https://support.mozilla.org/en-US/kb/dedicated-profile-thunderbird-installation

There is a particular set method to being able to go back to the last 68 version after updating to a 78 version. Because there even more chnages to the address book file format.

Need to set updates to ask, change the address book, uninstall, then download old and reinstall, but do not auto start. Then use command line to force a backwards compatibily allowance.

In the 78 version:

  • Menu app icon > Options > General
  • Scroll down to 'Updates' section
  • select 'check for updates, but let me choose whether to install them'


To add also those email addresses back follow below steps: In Thunderbird

  • Help >Troubleshooting Information.

Under Application Basics section about 8 down in list see 'Profile Folder'.

  • Click on 'Open Folder'

A new window opens showing the contents of your profile name folder.

  • Exit Thunderbird

In the profile name folder - you will find the old address book files with extension .mab.bak - those files (abook and history) you need to:

  • -rename them to .mab (so remove the .bak part) eg: 'abook.mab.bak' becomes 'abook.mab'
  • -rename abook.sqlite and history.sqlite by adding .bak to the name. eg: abook.sqlite.bak
  • Do same for any other address books you created.


Now uninstall Thunderbird program. You could just delete the Mozilla Thunderbird folder from here:

  • C:\ Program Files (x86)\Mozilla Thunderbird
  • then empty the computer 'Recycle Bin'

Then get download from here:

Run the downloaded .exe file to install. On the last step of the installation do NOT select to start TB because you will need to run a command to allow you to downgrade.

Windows OS:

  • In search type : Run
  • Select the 'Run' app
  • Type: thunderbird.exe -P --allow-downgrade

note there is a space before and after -P

  • click on OK

Profile Manager starts select the desired profile name click on 'Start Thunderbird'.