To Clear the Cache When the Black Admin menu disappeared from top of webpages ...
- During Development the cache is filling up much quicker than it would under normal use
- Regularly clear the cache to avoid having the menu disappear: Configure > Development > Performance > Clear Cache
- To access the menu if there is not the black admin menu available at the top of the window:
- 'Sometimes' adding /user to the end of the home page URL will bring the top admin menu back
- Drupal Summary of Issue: https://www.drupal.org/node/442560