there are 2 main reasons why toolbars don’t stick :
- either you’re not quitting properly
- or it wasn’t installed properly.
The first one, the interface is saved when you properly quit sketchup. if sketchup crashes, no go.
if you have several sketchup instances opened at the same time, only the last one you quit will keep its interface.
the second one, when installing, you should right click on the installer and install as an admin. that way, all the authorisations are given to SU. if not, then SU could not have access to certain folders, making it impossible to keep track of certain things.
You could simply download the installer again, right click on it, run as admin, and here choose repair.
there are no more versions since 2021.
sketchup 21, 22, 23 and 24 can open each other’s files without any conversion needed. you’ll have a message telling you it was made more recently, just in case, but it opens fine.
if you REALLY need to save to an older version (2020 and older) there are solutions / extensions.