i received this error message when i was trying to install admin_menu in drupal 8 can any one else help me to resolve this error ..
Fatal error: Cannot instantiate interface Drupal\Core\Cache\CacheBackendInterface in C:\xampp5.6\htdocs\drupal-8\core\lib\Drupal\Component\DependencyInjection\Container.php on line 268
This is one of the known error in Drupal port and needs work.
variable_set('admin_menu_cache_client', FALSE);
variable_set is depreciated in Drupal8.
Details of the issue can be found at: https://www.drupal.org/node/2563867