For some reason, every time I turn off my computer and turn it back on again, Traktor no longer communicates with my S4 MK3. I've done all the suggested stuff, which is how I came to discover that uninstalling/reinstalling the Controller Editor is what resolves this issue.
I really just wish I didn't have to do it every time I turned my computer on. Any thoughts on why I keep having to do that? Everything is up to date.