I have two Macs, the first running iMovie 10.1.2 and the second running iMovie 10.1.8. I completely copied the iMovie Library folder from the first machine to the second. When I opened iMovie on the new machine it showed some progress in recognizing the new library, and then opened my project. At first, everything looked fine, but then I noticed that some of the sound clips had no sound in them. I see the green rectangle for the correct duration, but there is no waveform displayed in it, and when I play it there is no sound. When I reveal the source the original clip there is no sound there either.
It seems like roughly half of the sound is missing. But the thing is, it's all from the same source file. I compared the imported media file and it's identical to the original. Furthermore, the sound is present in the actual media file. I tried deleting the extra directories in the event directory (Analysis Files, CurrentVersion.imovieevent, and Render Files) and it was able to "repair" the event, but the sound is still missing.
How can I get my sound back?!
Edit: I enabled viewing the waveform in the event viewer, and it appears that the sound abruptly ends at 54.7 minutes.