To Second Daniel's advice,
Yes, RDI 9.8 requires a new activation kit (if installed as a standalone).
Advice here is also to install RDI 9.8 in a different directory and back up the workspace. Use the backup workspace on RDI 9.8, as it will convert it. Test, and once you are satisfied, then uninstall 9.6 (they can run alongside each other; for example, RDI 9.8 uses a different installation method).
Hope this helps.
Marius