Is there a free update for FCP X to make it work with the new MAC Os?
Is there a free update for FCP X to make it work with the new MAC OS?
iMac (27-inch, Late 2013), OS X El Capitan (10.11.3)
The current version 10.3.4 works with High Sierra (macOS 10.13.*).
It came out a while before High Sierra and does seem to have a few problems, though, but it generally works.
A new version, 10.4, has been announced to launch later this year.
All updates since 10.0 until now have been free. I did not see it in writing anywhere, but I believe 10.4 will also be a free update.