Hello,
I would like to go back from the current version of Thunderbird (115) to an older one (102), because the new version breaks some addons and some user interface customisation I had, done in userChrome.css. I would also like to exclude it from updates in discover.
I am on an up to date KDE Neon, and Thunderbird is the one that is normally preinstalled in Neon (updated, of course).
How do I accomplish this?
Thanks.
One method is to use the binary release from Mozilla itself 
http://ftp.mozilla.org/pub/thunderbird/releases/102.15.1/
Ok, I downloaded the Tar.bz file. How do I use it? I know hardly anything at all about making this the default mail application, for instance, or installing it so that it has shortcuts on the desktop and in the main menu…
See the part for advanced users and adapt it to KDE Neon
Edit: And as the following posts say - it could be only a temporary solution and not recommended in a longer run
IMO, if you can’t figure it out on your own, it’s probably a bad idea to push ahead with it, and you should try to adapt to the new Thunderbird’s layout, or else customize it to suit your purposes. If you can’t, then continuing to use the old version is not a real solution as it will never get any bug fixes, security patches, or new features, and will eventually stop working at a random time when the rest of your system libraries are too new to support it. This will be quite jarring and traumatic, as one day it will simply stop working with no warning in an extremely disruptive manner.
So basically, your practical options are to get used to the new Thunderbird, or find a new email program.
Yes, indeed. Bad idea. As ngraham pointed out, it’ll fail eventually. In regards to the css, mozilla has a perverted way of constantly changing the css parameters. You should see the userchrome I’ve been dragging along . Would have to clean it up really cause it has more #'es and /* than anything else these days.
Thank you for your advice.
I am thinking that maybe I could adapt the old UserChrome file to use the new css selectors, because my old customisations were fonts and font colours, nothing fancy, but I would need to find what the new selectors are. Do you know where I could find this information?
As for the addons, I would very much like to replace the More Layouts addon, specifically the option to put attachments at the top of the message. I was not able to find an adequate replacement for this… The rest of the addons, I could perhaps do without…
Pretty much the same as firefox. You might wanna look up some or maybe get predefined styles. https://www.youtube.com/watch?v=bw_M7q3Mtag
https://firefox-source-docs.mozilla.org/devtools-user/browser_toolbox/index.html
