: FCP 7 runs best on Mac OS X 10.6 (Snow Leopard) through 10.10 (Yosemite).
Here is the safest workflow for legacy use:
Let’s address the elephant in the room. Apple never released FCP7 as a public DMG download. The original distribution was via (7 discs for the full suite, or 1 double-layer DVD for the app alone). Over time, users converted these DVDs into DMG files for convenience.
Finding a legitimate "Final Cut Pro 7 DMG" today is nearly impossible through official channels, as Apple ceased sales in 2011 and ended all support in 2017.