Final Cut Pro 7: File Error: Unknown file The sequence is composed of a jpg followed by an mp4. When the jpg is not present, after I hit Command + R, the sequence can render without errors. When the jpg is present, after I hit Command + R, the sequence cannot render and it returns a message "File Error: Unknown file."
Final Cut Pro may not recognize your file location. Did you change the location of the jpg after you imported it into the sequence? If so, you may have to locate it again.