iMovie 10.1.4 does require OS X 10.11.2 or later. In honor of Apple's inconsistent version numbering of the iLife apps, I offer the following concerning iMovie:
- iMovie '09 January 27, 2009
- Bundled with all new Macs and for separate purchase (iLife '09)
- Mac OS X 10.5 (Leopard) and Mac OS X 10.6 (Snow Leopard)
- Bundled as part of the iLife '09 package.
- iMovie '11 October 20, 2010.
- Bundled with all new Macs sold on or after October 20, 2010 or for separate purchase in iLife '11.
- Mac OS X 10.6 (Snow Leopard), Mac OS X 10.7 (Lion), Mac OS X 10.8 (Mountain Lion) and Mac OS X 10.9 (Mavericks).
- Bundled as part of the iLife '11 package. Also available for purchase in the Mac App Store.
- iMovie 10.0 October 22, 2013
- Bundled with all new Macs and for separate purchase from the Mac App Store. Mac OS X 10.9 (Mavericks) and later.
The last version available for Mac OS X Mavericks (10.9 and later) is version10.0.5. Movie 10.0 was released on October 22, 2013 by Apple Inc. This version of iMovie was a complete redesign with more options to share a movie, more movie and trailer theme options from iMovie for iOS, easier to make picture-in-pictures, cutaways, side-by-sides etc., more realistic green-screen effects and easier refinements. Wikipedia/iMovie
Finally, while you
can find several sites offering a download of iMovie 10.0.5, I cannot, in good conscience, recommend any of them. There are simply too many malware-infected files available out there, even malware for a Mac!
It
may be possible to use the Mac App Store and find a newer version of iMovie than the one you have. Open MAS and use the "Purchased" tab, click (or double-click) the iMovies item and see if a newer version is available for your machine.