All our current Melodyne (singletrack) editions are built to be backwards-compatible and can open older Melodyne plugin files (and downwards-compatbile for different Melodyne editions). Just make sure that the folder structure and file paths on your system are the same as before. Also, do not delete the Transfer folder or any files in there.
Obviously, after a system crash or after reinstalling or upgrading your complete setup, your file paths or folder contents might have changed, so this could easily be an explanation for Melodyne not finding the required files automatically. In these cases, you can reassign missing files. See this tour
from our online manual.