Using Lightroom 2.4.1 trying to 'Save to' CR2 images as JPEGS to a desktop folder. Of my 530 images, 170 fail. A box appears with "Export Result - Some export operations were not performed" It then lists the file names. I have tried saving as a small size JPEG file, saving files individually, closing and re-opening program. I am on a mac OS 10.12.