If your Mac is stuck with High Sierra , you can’t upgrade it and you want to install iMovie ? follow the steps below:
Installing iMovie9
# 1. Download the iMovie 9.0.9 update package
curl 'https://updates.cdn-apple.com/2019/cert/041-98154-20191017-1fbef983-8d87-49af-83b1-edecc007ce2e/iMovie9.0.9Update.dmg' -o ~/Downloads/iMovie9.0.9Update.dmg
# 2. Mount the dmg
open ~/Downloads/iMovie9.0.9Update.dmg
# 3. Expand (unarchive) the pkg
pkgutil --expand /Volumes/iMovie\ 9.0.9/iMovie9.0.9Update.pkg ~/Downloads/iMovie/
# 4. Rename `Payload` to `Payload.zip`
mv ~/Downloads/iMovie/iMovie9.0.9Update.pkg/Payload ~/Downloads/iMovie/iMovie9.0.9Update.pkg/Payload.zip
# 5. Unpack `Payload.zip` (it will get named `Payload 2`)
open ~/Downloads/iMovie/iMovie9.0.9Update.pkg/Payload.zip
# 6. Move `iMovie.app` to the `Applications` folder
mv ~/Downloads/iMovie/iMovie9.0.9Update.pkg/Payload\ 2/Applications/iMovie.app /Applications/iMovie\ 9.0.9.app
# Enjoy!
open /Applications/iMovie\ 9.0.9.app
If you want to upgrade to iMovie 10, follow the steps below:
# 1. Check whether your App Store contains iMovie in tab "Purchased"
(You should see iMovie with button upgrade, If you don't see you should
turn on iMovie)
# 2. turn off iMove 9 and App store.
# 3. move to trash iMovie 9
# 4. Open App Store, go to "Purchases" tab and click "Install"