Just upgraded from Sierra to High Sierra. Running Parallels 13 and Toolbox V3. Now says Licence key is invalid. Have tried to use my Parallels 13 Licence key - says I am trying to use a licence key created for an older version of Toolbox I need to upgrade my Toolbox licence. Need to upgrade to 13 or higher. I am using a V13 activation key. Have tried this suggested fix via Terminal: defaults remove ~/Library/Preferences/com.parallels.toolbox.plist SavedProductVersion No difference.