Sorry for reviving this old thread, but I think it's worth it…
I started to get this "Unfortunately, Cocktailbar service has stopped" error on my Galaxy Note Edge (SM-N915G) yesterday (May 9, 2019). Samsung Music app was auto-updated (to version 16.2.17.19, according to Google Play) just before this started to happen, so I already suspected that's what causing the issue. And indeed, reverting it to the factory version immediately fixed the issue. So, looks like Samsung has made this bug once again.
05-10-2019 08:57 AM