Sorry maybe my problem wasn’t really clear.
I’m trying to open and then update old libraries so they will all run on current 10.4.10 version.
It looks like anything from 10.2 upwards will automatically update if I open the older library in 10.4.10, so I won’t actually need to install FCPX3 at all.
However, I have some really old stuff edited in a 10.1.X version with the original folder structure of Projects and Events, and I can’t see any way to open those in 10.4.10
So I was hoping I could install 10.2.3 on same machine just to update these to FCPX2 library format and then open them in 10.4.10 and update that way (my original question was to see if there’d be any problem in doing this).
But now, on doing a bit more research to clarify the issue, I see that 10.2.3 won’t actually run on High Sierra and above, and I’m on Mojave, so that solution isn’t going to happen anyway.
There’s no way of opening those early libraries on a current system is there?
Looks like I have to try and get hold of an older operating system, install that onto some external drive, install 10.2.3 on that and get the Project/Event folders updated into libraries.
What a horrible lack of backward compatibility. Anyone got a quicker fix?