I am updating a Drupal 8 website to the latest version 8.2.4 and I am having this error.
The installed schema version does not meet the minimum. Your system schema version is -1. Updating directly from a schema version prior to 8000 is not supported. You must migrate your site to Drupal 8 first.
It's not an upgrade from Drupal 7 to , it's and update from 8.2.1 to 8.2.4. Find image here
