Radical Piano was an RE... Log into your account and look for them.
Use the RE manager to check what RE's you have and if you find them, remove them and re-download them.
If you have purchased the Rack Extension, you can download it again at any time from your user account at the Propellerhead web site and reinstall it if you want.
See this video... 32 seconds in.
https://youtu.be/9L9GW_M56j0?t=31