This was, unfortunately, a bug in Racket that was present in v6.2.1. It has since been fixed (by me, in this commit), but given that you have a version with the bug, you’ll have to update it manually.
Each installation of Racket basically exists within its own sandbox, though, so you should be able to install the new version alongside v6.2.1 without any problems, and you can check if it works. Things like settings will be preserved across versions, but installed packages will not be.
I think DrRacket may prompt you to migrate your packages when you launch a new version, but I honestly forget. However, you can manually migrate your old packages from another version using the raco pkg migrate command. Otherwise, it’s not much of a loss—you can always just reinstall them.
Once you’ve migrated your packages (or decided you don’t want or need to), you can safely delete your old installation’s directory.