Imovie media disappeared from the event.

Clips that were in my event have been replaced with a "missing camera" message.

I found the clips in the iMovie library, by right-clicking and selecting "show package contents". The videos were there, so I copied them to a different folder and tried to import them into a new event. That failed, yielding only a message that I must import/reimport the file.

So, I copied the MVI-****.mov files back onto the camera flash card and then imported them again into a new event.

That seems to have worked, so far.

My questions are:

1: Why does this happen? and

2. Is there a way to restore the clips to the event without going through that. I mean, the clips are clearly right there in the library.

Thanks.