SOLVED!!
After migrating from El Capitan to High Sierra, my "Parallels 14 could not be started". After several hour on the telephone with Parallels support and after trying many different things, the problem was resolved by reinstalling the MacOS High Sierra.
Perhaps the OS did not install correctly because I jumped two steps from El Capitan to High Sierra??
THE Steps to reinstall MacOS:
1) Restart Mac is Recovery mode. Press Windows key + R after restart.
2) Choose Reinstall MacOS from menu.
3) Pray.
Last edited: Dec 14, 2018