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Release Notes & Migration from Release Channel to ESR

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  • Last reply by rsbrux

rsbrux
rsbrux

1. Where can I find the release notes for Thunderbird versions?

2. I mistakenly installed v148.0 from the release channel, when I really want the ESR version. This article says, " "Still unsure which channel to use? Start with the Thunderbird Release channel. You can always switch later if your needs change." and this thread says that one can perform the necessary downgrade by simply deleting the compatiblity.ini file from the profile folder. However, the current release channel version (149) and the version I have installed (148.0.1) are far ahead of the ESR version (140.8.1). I have already configured 8 IMAP accounts and 4 add-ons and would like to retain my existing profile. Can I simply downgrade by deleting the compatiblity.ini file from the profile folder or do I risk data corruption due to changes to the data structures? Can I simply install ESR 140.8.1 over 148.0.1 or do I first need to uninstall 148.0.1?

1. Where can I find the release notes for Thunderbird versions? 2. I mistakenly installed v148.0 from the release channel, when I really want the ESR version. [https://support.mozilla.org/en-US/kb/choosing-thunderbird-release-channel#thunderbird:win11:tb149 This article] says, " "Still unsure which channel to use? Start with the Thunderbird Release channel. You can always switch later if your needs change." and [https://support.mozilla.org/gl/questions/1553339 this thread] says that one can perform the necessary downgrade by simply deleting the compatiblity.ini file from the profile folder. However, the current release channel version (149) and the version I have installed (148.0.1) are far ahead of the ESR version (140.8.1). I have already configured 8 IMAP accounts and 4 add-ons and would like to retain my existing profile. Can I simply downgrade by deleting the compatiblity.ini file from the profile folder or do I risk data corruption due to changes to the data structures? Can I simply install ESR 140.8.1 over 148.0.1 or do I first need to uninstall 148.0.1?

Chosen solution

This article indicates you can install the ESR over the monthly. https://blog.thunderbird.net/2025/03/thunderbird-release-channel-update/ and removing the compatibility.ini file should suffice. However, I always recommend being safe. That is, before any significant change:

  1. exit thunderbird ]
  2. do a backup for safety

Steps for backup are here:::

  1. ensure thunderbird is not running
  2. enter %appdata% in search window on task bar and press Enter key
  3. this should open windows file explorer in Appdata\roaming folder
  4. highlight the Thunderbird folder and copy to external media or another folder away from the thunderbird folder
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david
david
  • Top 10 Contributor

Chosen Solution

This article indicates you can install the ESR over the monthly. https://blog.thunderbird.net/2025/03/thunderbird-release-channel-update/ and removing the compatibility.ini file should suffice. However, I always recommend being safe. That is, before any significant change:

  1. exit thunderbird ]
  2. do a backup for safety

Steps for backup are here:::

  1. ensure thunderbird is not running
  2. enter %appdata% in search window on task bar and press Enter key
  3. this should open windows file explorer in Appdata\roaming folder
  4. highlight the Thunderbird folder and copy to external media or another folder away from the thunderbird folder
rsbrux
rsbrux Question owner

Following (I hope) your instructions and those in the linked article (and its sub-linked articles) I have:

  1. backed up Thunderbird's data (while Thunderbird was closed).
  2. Installed 140.8.1esr
  3. verified that C:\Program Files\Mozilla Thunderbird\thunderbird.exe is indeed 140.8.1
  4. started it via C:\Program Files\Mozilla Thunderbird\thunderbird.exe -allow-downgrade

My previous profile came up and I received (often overlapping) prompts for authentication of my IMAP, Calendar and contacts accounts. After logging into all of the provided prompts and authorizing Thunderbird to read my Google Workspace (GWS) Calendar and Contacts, I find that most of the IMAP accounts work (including two Google accounts). However my Apple (me.com) account fails to login, as does my GWS calendar, even though I gave Thunderbird the needed permission in the Google popup. Thanks for your help!

P.S. The Apple account needed an application-specific password. After rebooting, the GWS started working again. I am surprised and disappointed that these things weren't carried over from the previous installation, where everything was working.

Modified by rsbrux

James
James
  • Moderator
  • Top 10 Contributor

rsbrux said
1. Where can I find the release notes for Thunderbird versions?

Thunderbird Release notes is listed on https://www.thunderbird.net/thunderbird/releases/

rsbrux
rsbrux Question owner

I take it back: the Contacts integration is not working. The Thunderbird native Contacts module will only allow me to view, print or delete contacts from GWS. The CardBook add-on allows me to edit them, but synchronization is evidently one-way: it discards the edits. This used to work both ways in the previous installation.

Modified by rsbrux

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