Example problem: Configuration bootstrap_sass_starterkit.settings depends on the bootstrap_sass_starterkit extension that will not be installed after import.
Solution: delete the bootstrap_sass_starterkit.settings.yml file from the config/sync directory
https://medium.com/@ChandeepKhosa/my-experiences-with-drupal-8-configur…
and if that doesn't work just delete the files from the config directory.