I've tried to explain as much a I can! https://discussions.apple.com/message/21152836#21152836 I've got a mid 2012 MBP, 13", 2.5Ghz, intel Core i5 running 10.8.2. My version of iMovie is: iMovie 11 - 9.0.8. Over the past few months I've been downloading the clips I want from youtube, (they are episodes of a series, I like to make video's from). Yesterday I had finally downloaded them all so I imported all the clips to iMovie, in the hope of making videos like I did on my old mac. Only I quickly noticed a few problems: - sometimes in the viewing window the clips would not show, only their sound would play - sometimes they clips would show but no sound - sometimes, if I moved my mouse over the clips in the events (not on the viewing window), one would get stuck and kind of move over all the rest - if I dragged a clip to the editing section, it still wouldn't show on the viewer, and sometimes no sound would play either Basically it was all messed up. So I deleted all the clips, and restarted, this time ordering them, and importing them into separate events by the year they are from. Still the same problem. So I found this from a previous discussion telling me to: I'm not sure if the following is a permanent fix, but so far it has solved my problem. Mine is MBP CoreDuo 2.0Ghz with 2GB ram / iMovie'08 on Leopard 10.5.5 Here's what I did to work around the "black preview" in my iMovie, and it's easy. 1. First, move the entire "iMovie Events" folder (in the Username/Movies by default) somewhere else. (I put it on my desktop) 2. Then, reimport each event back to iMovie using iMovie's "Import Movies" feature. Do import events individually although it takes more time. 3. During import, select only the clips you want. Don't select "iMovie Cache" & "iMovie Thumbnails" created by the first import. 4. Voila! Those black clips should appear again in the iMovie's preview window. Extra finding: Before making the steps above, I had an iMovie project whose edited content wouldn't display either. After moving the "iMovie Events" folder to my desktop, the project showed a warning sign (little yellow triangle). However, after reimporting the exact clips back to iMovie, not only can I view the clips separately again, the original project plays normally again. ------------- I haven't yet done this, however I did move my entire iMovie events folder to my desktop. I was going to ask, surely the events would still be in iMovie, so how do you reimport them without deleting them (as then you have nothing to import) but I realizing when I then opened iMovie and it said the source clip was missing and non of my events seem to be in iMovie. Should I keep the folder on my desktop, and now reimport the events individually (not clips individually, but the events by year?) Edit: Phoned apple. iPhoto clips seem to work, but a clip I had from my old camera - only the video worked, not the audio. Something is definitely playing up.