Final Cut Pro Rendering ERROR - 10004

The bad frame is likely the very first frame of one of your imported clips. You can easily find it by jumping through your project using the ' key and when you hit one that displays black, cut that frame out.

I have this problem occasionally when importing AVCHD video (like one clip in ten) but do not get it at all when I set my camera to MP4.

If you want to see exactly where it failed, export in Apple Devices Format (any resolution is fine) and when it fails, it will finalize a .m4v file that ends at the last good frame.

Try deleting the Project render files.

Click the Project icon in the Browser then Delete:

You don't need to render to export.

If the issue is a bad frame number change the time display to frames in Preferences>General>FCP X:

Al