Does FCP 10.2 it work with OS X 10.10.3

The latest version of FCP X, 10.2, requires 10.10.2 or 10.10.3 to run.

I have been running on 10.10.3 without incident.

This was a substantial update, and I am very happy with it, but a number of problems have been reported - some with plugins and more acutely problems with mostly Panasonic cameras.

As always, two important pieces of common sense advice for any update:

1) Don't update if you are in the middle of an important project

2) Have a complete and confirmed working backup.

That said, the improvements in this version are awesome. Most people will probably talk about 3D titles (and they did it sublimely well, in my huble opinion), but that alas has a tremendous potential for abuse (as in bad taste 3D for no reason). For me, the masking capabilities available consistently for *any* effect are amazing. The library-wide smart collections, an important help in organization. Plus many little things.

Of course, all is moot if you are one of the (few) people for which the update meant a lot of grief. But as long as abide by 1) and 2) above, you'll be safe (and Murphy's law says that problems are then *less* likely :-))

TThere is no update path. You simply have to purchase the application from the App Store. You might want to get the trial version first.

but why doesn't my older FCP work with the new updated Yosemite 10.10 5? Does this mean even though I spent over $200 for the FCP - now I have to spend $299 for the new one???

What FCP did you buy for 200 that doesn't work? FCP7 works with Yosemite.

10.0.9

IF you bought 10.0.9 from Apple, the upgrade is free.