Thanks Lloyd S and Noel, I should have said that I can render a video using the "Save As" and using the CVSM:MS-CRAM codec, however when I come to play it I get a Missing Codec error message, so that's another issue.

The VJT error only happens when I use the Video tab on the main menu, I think I'll install 2018 as it did work for me then.

Thanks
Keith