iMovie out of application memory

The application memory is the amount of space on your drive (your internal drive, assuming that is where the app is located) that is taken up by, or required for, operation of the app. The iMovie app itself takes up less than 3GB of space because all of the media in the project is stored in the separate iMovie library. From your screen shot it looks like you have a large movie project that, when exported to your internal drive, will exceed the amount of free space available.

So, to cover the bases, check the amount of free space available on your internal drive and your destination drive, if different, and confirm that you have enough free space. You might also try exporting the project to an external drive that has sufficient free space, and see if that makes any difference.

-- Rich

Try shutting down and rebooting.

If the problem persists, rule out a hardware issue. Try running the hardware diagnostic that is on your Mac.

What happens if you ignore the error message?

-- Rich

Hmmmm. You might benefit from contacting Apple Support and talking to the techs there. They have the capability of remotely accessing your computer that we do not have here.

-- Rich