I was using one of the older versions of Thunderbird (76) but I had to start using the latest version (86) because I needed it to sync with my work email. I am running a debian-based Linux distribution. The older version was installed through the package manager, but the newest beta release came with the executable in the folder I downloaded. I therefore never really 'installed' it, I am just running the executable and everything is working fine. My questions are: 1. How can I transfer my personal Thunderbird calendar from my older Thunderbird? I have other calendars elsewhere which I have already synced to the newest release, but the Thunderbird-specific calendar I was using in the older release seems to be gone. I found a folder inside the hidden .thunderbird folder called 'tvpkve6n.default-default'. Inside it, I see a folder called 'calendar-data'. I thought copying this folder to the current folder of the beta release would do the trick, but that didn't work. I also copied it to a beta folder inside the hidden .thunderbird folder, but that also did not work. Any suggestions? 2. How can I import my saved list of contacts from the older to the newest release? I couldn't find the file where my contacts are saved, and now every time I have to write an email I have to first go find that person's email, which is quite frustrating. 3. I now seem to have two instances of Thunderbird installed on my computer, which doesn't seem right. In the forum of my linux distribution, I was adviced to not run the older release again, because that might break the functioning of the newest release I am currently using. How can I 'install' the newest beta release, so every time I open, or update, Thunderbird, I will be using the newest release only? Thanks in advance for the help!