While dealing with a very odd problem in Final Cut Pro with a customer in my daily Apple Tech job, I came across what seems to be a common problem that has many people in dozens of forums seemingly dangling for an answer.
Final Cut Pro (4.5 and HD) displays this:
When Final Cut Pro or Final Cut Pro HD displays a "Preview Disabled" error message with a color bar in your log and capture window - the fix is just to reinstall Quicktime.
Just go to:
Other troubleshooting that I tried before I arrived at this conclusion:
* Searched the web ... Googled for "Preview Disabled Final Cut Pro" <-- no clear answer
* Tried a different firewire cable going to the DV camera <-- always good to do
* Made sure I had only the DV camera plugged in to firewire <-- worth a try
* Turned off capture hard drive <-- try to eliminate hardware problems
* Toggled various settings for NTSC & firewire within Final Cut Pro <-- this was useless & unnecessary
* Ran Disk Utility - Hard Drive/Applications/Utilities/Disk Utility <-- always good to do
* Made sure all updates were applied - Apple Menu/Software Update <-- always good to do*
* Before you download any software it's best to do your homework first. I usually go to XLR8YourMac.COM and read the notes from various commenters and Mike's excellent followups for about a week before I download ANY operating system or iTunes updates.
This problem is very odd because you can see the time code running and you can control the camera, but nothing happens on your "log & capture" preview screen after pulling it up from the file menu. It seems at first as though it were a hardware problem. Forum after forum suggested that it was a settings issue.
It seems this is a common problem that crops up after users download updates. The 10.4.8 update seemed to have a few threads after it was released and the forums seemed to have new activity starting two weeks ago when the 10.4.9 update came out. Don't forget that all iTunes updates usually carry a Quicktime update or at the very least alter Quicktime in some way ... so even if you update iTunes ... make sure you REINSTALL the latest version of Quicktime. It's best to just bookmark the link above and have it handy.
9 times out of 10 I have discovered that if you are experiencing problems with iMovie, Final Cut Pro HD, or any video editing program .... reinstalling Quicktime seperately (even if you recently updated) is always good to do. It's also good to run Disk Utility after you run the installer.
If you are having any problems with Final Cut or Final Cut Pro ... please don't hesitate to post a message here ... I'll see if I can help or ask one of my many Video editing customers.