The Missing Media error screen may be a result of corrupted macOS disk permissions.
To fix them, please try the following:
- Close all applications running in the background (especially Motion and FCP), otherwise the files and folders that are in use will be omitted,
- Open mInstaller and uninstall the plugin,
- Go to our app's Settings via the Cogwheel Menu, [Repair] your Disk Permissions and [Clear] mInstaller's preferences (do not log back in onto the app just yet),
- Open the Disk Utility (you'll find it in your Applications > Utilities folder), select your disk in the menu on the left side of the app's screen and press "First Aid",
- Select the partition below your disk, press First Aid again and, once the process has been finalized, close the Disk Utility. If you do not see any partitions, then you'll need to change your view to "Show all devices" via the menu in the top left corner of the app.
Next, reboot your Mac, log onto mInstaller, install previously uninstalled plugin and check if anything has changed.
If not, then please re-install the plugin via the PKG installer that can be downloaded from your My Products page.