iMovie issues exporting files

Typical things that prevent a full export are insufficient application space, a corrupt frame somewhere in the project, an incompatible clip (such as legacy media). A corrupt preference could also cause it.

Try deleting/resetting preferences and see if that solves it. To delete/reset preferences open iMovie while holding down the Option and Command keys and select to delete preferences in the box that appears. iMovie will open in a new library. Reopen your old library to get back to your projects.  Deleting preferences is a safe procedure that will not cause data loss or disruption to your project.

-- Rich

The application space is the space on your internal drive where your application (i.e, iMovie) is located. While iMovie can function at 10GB, or even 5GB, available free space on the drive, it is best to have 20GB or more, particularly if you editing a large movie.

Click on Apple Logo/About This Mac/Storage to see the available free space on your internal drive.

-- Rich

Did you try exporting to File rather than You Tube & Facebook?

Since other projects exported fine, and even your recent ones on an older computer, but just not the recent ones on your new computer, is it possible that there are legacy files contained in the newer vids? For axample an .avi file would be a legacy file that might not work with the current 64 bit operating system, like Monterey. Yet it would export fine on an older computer.

-- Rich

Hmmm. That should not be happening.

I suggest that you contact Apple Support where the techs there have the capability of remotely accessing your computer, that we cannot do here. To contact Support, click on the Get Support item in the upper right hand corner of this forum's screen and navigate to a place where you can enter you phone number. The Apple Support techs are pretty savvy and may be apple to solve your issue.

-- Rich

Try creating a new project and exporting from the new project.

Also, try exporting as a file to your desktop.

-- Rich