per suggestion I upgraded my Win10 machine from Kicad 5.1.6 to Kicad 6. The installation was able to detect most of the settings of the old installation. The global library paths needed to be set manually, but the footprints and models are all there.
My recent projects all opened correctly (with the prompt that it will be saved as current version). So far I like the new ‘feel’. It seems more responsive and faster.
Now. What to do with the old version? I thought there will be an prompt to uninstall the old one. Is it safe to uninstall the old version?
Running v5 uninstaller will remove v5 libraries only if these were installed by v5 installer (but I see no reason to keep v5 stock libraries, it is better to install newer stock libraries with full v6 installer). Uninstaller will not alter any other v6 confugurations (already imported from v5), so it or safe to just uninstall v5 by uninstaller. In case you have custom eeschema bom plugins, these were installed inside v5 program files dir, so probably they will be removed by uninstaller, you should backups them.
KiCad V5 is very much dependent on the libraries for schematic symbols.
Some time ago (years) the [Project]-cache.lib was invented as an ad-hoc method to cache all used schematic symbols of a project. If both that file and the original libraries are missing, your schematic is not viewable, you get the dreaded [??] symbols in the schematic. This is repairable, but it needs the original libraries for that. In KiCad V6 this is no longer an issue because all parts of a schematic symbol are saved in the schematic itself.
This is only for the Schematic. The PCB file has had the footprints embedded in the file for a long time.
The schematic symbol libraries are also not very big. Most of the (approx 4GB) of libraries in KiCad are for the 3D models.
Another small thing is that KiCad V6 does not migrate old KiCad V5 libraries. You must do so yourself if you wish to.
(@v3xX , I only partially wrote this for you, but mostly for others who will be searching the forum in the foreseeable future).
To the topic:
Uninstallation of Kicad 5 on WIn10 was no Problem. So far no noticeable changes in my projects. Upgrading to Kicad6 in Ubuntu was even more convenient. Using this link upgrading was no problem. The old version was replaced and works out of the box.
Back to work.
EDIT: Even migrating custom (old) symbol and footprint libraries was no problem. Everything was prompted or guided. I am truly amazed how sophisticated this software has become
Mint was even easier.
6.0.0 and later 6.0.1 both appeared in the Mint “update manager”… didn’t even have to go to the link.
The most common problem incurred seems to be clicking “no” to the installation of the Kicad libraries, which then required a re-install with a "yes’ to the libraries.