Hi...
Sadly it isn't possible to open files saved in a newer generation product in an older generation. For example, files saved in iClone 8 can't be opened in iClone 7, files saved in CTA5 can't be opened in CTA4. This has always been the case with every new major version upgrade.
So generally you will find file compatibility between iClone 8 and CTA5 and as you have found also between iClone 7 and CTA4.
Peter
Forum Administrator
www.reallusion.com