This is a pesky error that has been reported numerous times. There doesn't seem to be any one cure. Take a look at these threads and see if any of the procedures described there help you.
2017 com.apple.Compressor.CompressorKit.ErrorDomain error
com.apple.Compressor.CompressorKit.ErrorDomain error -1 with iMovie !!
From reading the posts on this forum, the restart in Safe Mode, and immediate reboot in regular mode, seems to be the most successful cure, but you have already tried that.
One poster solved the issue by importing the media to his desktop rather than directly into iMovie, then changing the name of the clip, and dragging it into iMovie. He was able to share without the error message.
You can try opening iMovie in a new user account, such as the Guest account on your Mac.
You can also try opening iMovie while holding down the Option and Command keys, and selecting to delete preferences in the box that appears.
If you find a cure, please post back if you have time, as it might help others deal with this issue.
Good luck with this.
-- Rich
