Hi, christachoo_,
You didn't mention, but I assume that you are using iMovie 10.
When more space is needed, the solution is to purchase an external drive, format it Mac OS Extended (Journaled) or APFS, and move your iMovie Library to it. By transferring the iMovie files out of the iMovie Library you likely corrupted the library and made the projects unusable.
Neither an iMovie Library nor an iMovie project in editable form can be stored in the cloud. An exported movie can be stored in the clould. The media contained in an iMovie project can be stored in the cloud, although iMovie will not be able to reference it there because it is not contained in an iMovie Library.
You cannot open anything with "CurrentVersion.imovie event". Where did you find that folder? I'm not sure exactly what you did when you say you deleted projects and then tried to open them. If you deleted the project they could not then be opened. Can you provide more details as to the steps you took to do what you did?
Are you possibly working within the iMovie Library Show Package Contents in your Finder? If so, you should never do that. Moving, altering, renaming, or deleting anything from the Show Package Contents projects risks corrupting your library. No projects can be opened from the Show Package Contents folder. Each project in the Show Package Contents folder contains an Original Media folder that contains the project media, and the media can be played there. But if you deleted or moved any of the media, you would disable the project.
If you have corrupted your library you may be able to use your Time Machine Backup to restore it to an earlier point in time before you made the changes. Or, you can try going to the iMovie Baclups folder to see if you can open an earlier back of your library.
To get to the iMovie Backups folder, follow this file path from the Finder menu:
Go/Home/Library/Containers/com.apple.iMovieApp/Data/Library/Caches/iMovieBackups
When you get there you will see a list of previous backups of your iMovie library. Click on one dated just before
your issue started. iMovie will open in that library. Navigate to your projects browser (where your projects are displayed as icons) and see if your projects are intact.
You might also try contacting Apple Support and talking to the techs there. They have the capability of remotely accessing your computer, that we can't do here.
-- Rich
