Brandon Ryan [Cakewalk
]
I would absolutely dump and clean out every version of SONAR previous to 8.5.
I'm really surprised to see this advice posted without any caveats or details. It's well-established that uninstalling older versions of SONAR can take shared content with it that new versions are still using, even if you answer "no" to all the shared files prompts. I once did a successful uninstall of 8.0 to prove that an 8.5 install from download would continue working without it, but I had to back up all the Shared folders, and restore lost content after the uninstall to get everything back.
If you back up and restore the shared content, older versions can be safely uninstalled, but it's hardly worth the trouble for the small amount of disk space saved and the loss of access to older versions when you get errors opening or editing old projects in newer versions.
Also, it's necessary to manually remove registry branches and AppData content to really get things completely cleaned up, providing more opportunities for making costly mistakes.
IMO, it's just not worth the trouble and the risk unless maybe you're running an SSD with space at a premium.