Captivate 8 and .cp files

Where did you see that this is possible? Files with extension cp have disappeared with version 5, and mostly Captivate can only open files a couple of versions back. You should need an intermediate version (5 or 5.5) to try to convert the cp files to cptx files. Just want to warn: do not expect the conversion to be smooth at all, so much has been changed in Captivate over all those versions: 5 did see a big change in UI and was totally rewritten, no support for AS2 anymore. Many, many features were added and a new UI change occurred in CP8. On the whole it would probably be less time loss to recreate everything in 8 then converting the file twice (with the intermediate version) and trying to find all what is not working as expected. There has been at least 6 years since cp disappeared.