I got this prompt on Ubuntu:
How to do it?
Should I removed the current Kicad first then add the desired version of KiCad, or I could just install the latest edition when the elder edition hasn’t been removed:
sudo apt update && sudo apt upgrade
sudo add-apt-repository ppa:kicad/kicad-9.0-releases -y
sudo apt install kicad -y
see here for details:
it’s possible to make various KC versions coexist on one machine, but i suggest to stick with current version (9.0.2 at the time, 9.0.3 soon).
From the message i suspect the files have been opened with a nightly version, 9.99. If this is the case you only option is to install the most recent version of the nightly.
I see the date string 20230121 in your screenshot, and that’s two and a half years ago now, so you definitely don’t need the latest and greatest KiCad version for that project.
You do not need to uninstall an older version of KiCad before you install a new version. The installers are smart enough to work this out. However, your order of commands does not work. You have to update your package list after you’ve added the new repository, not before.
What is your Ubuntu version? I use 24.04 LTS and install kiCad 9.0.2 from a PPA
25.04 should also have a PPA.
The previous LTS 22.0.4 can run into trouble with Python and other dependencies
So I ran this command on Linux:
$ find play -name '*.kicad_sch' | xargs grep 'version 20230121' | less
Unfortunately picking one of the results to look at with a text editor didn’t show any KiCad version, but looking at the PDF of the schematic I left behind in the same directory showed that this schematic version corresponds to KiCad 7.0.9. So v7 and above can open this file.