How do I change the default theme with Drush-master

Question

I've installed a premium theme in a Drupal 8.1.0, and now each time I log into the site It crashes with the error "An unknown error has occurred" (even though the site itself works fine). I thus try to change it with Drush.

I've tried drush vset bartik in drush-master to change the non-admin theme back to bartik in Drupal 8 but then came the error:

[error]Command variable-set requires Drupal core version 6 or 7 to run.
[error] The drush command 'vset bartik' could not be executed.

Answer 1

Try this:

drush config-set system.theme default bartik

• You might need to clear or rebuild your CSS/JS and theme caches (drush cr).

• If the problem still appears, check that it has not been forced in your settings.php file.

Source: https://www.drupal.org/node/200774