Drupal - Unable to install ... already exist in active configuration

With drush you can probably do

drush config-delete module_name.settings

to delete the configurations that complain

Found module, use Easy Install module to purge active configuration without using devel or drush. It works even if you have missed out the optional folder and enforced option in your module's configuration files (yml)

I have same issue for pantheon site. I entered drush command

Pantheonsite: drush @pantheon.SITENAME.ENVNAME config-delete ERRORNAME

Localsite: drush config-delete ERRORNAME

it's work for me.