iMovie

I was working on an iMovie yesterday morning, it was large - 27 gigabytes. I closed it and shut down the computer (no problems or anything unusual there) and now it will not open. It appears to load, it shows the bar and goes through the various parts of the movie, but then iMovie quits. I can open other movies maybe because they are smaller.
I have the file saved on two external drives as well as the hard drive.
I've rebooted the computer many times and tried opening it without anything else running.
Any suggestions?

Sounds like the internal Project file is not able to load. RAM or OS file size limit, would be my first guess.

What OS X version, RAM and Mac do you have?

Staggering stuff, I would suggest asking iMovie to churn out a feature/HD movie is asking a bit much. If you're undertaking a Pro sized job maybe you need pro size tools. Or perhaps chop it into manageable chunks and use QT Pro to combine them at the end.