Error: "The file was created in a newer version", I just updated

When I launched Sketchup on Thursday-Friday I was advised to update to a new version, after doing so I can’t open some older files. I cannot open files created after end of January approximately, all files created before that date seem to open normally.
Please see attached screenshot of error message. I have tried to download the latest version two more times and update, to no avail.

It looks like you are opening SketchUp 8.

How many versions of SketchUp do you have installed ?
The error message says you are running v8 and trying to open a v2020 file…

What version of SketchUp were you running prior to the update ? You profile suggests v2020 ?
Was the update an update for MAC v2020 ?
Did you fully install that update ?

If you have v2020 installed, then open it and get its version from the Help/About menu…
With that version of SketchUp open, can you use it to navigate to and open the SKP that threw this error ?

Are you trying to open those files by double clicking on Finder, or do you launch SketchUp and then use the File menu?

If “open with” somehow got stuck on version 8, you can right-click a file on Finder, open “get info” and change it there for all skp files.

Nice to see that SketchUp 8 still works in Mojave, though not in Catalina.

Hey all, thanks for the answers! It seems like some old Sketchup version was still installed, I never thought it wouldn’t be removed when I upgraded to Sketchup Pro. It must have somehow hijacked my shortcut settings when I upgraded Sketchup Pro last week.

You can perfectly well have several versions of SketchUp installed on your computer at the same time. The default behaviour is that SketchUp model files get associated with the version you used last.

I understand that you can have several versions at the same time, I guess it was naive of me to suppose that a newer version would overwrite the older. File association changed automatically to the old version when I upgraded the newer Pro version.