"User does not exist in cache_keys. Try regenerating the cache" Error

Symptoms

When accessing some sections in WHM or cPanel, you are presented with this error:

User does not exist in cache_keys. Try regenerating the cache.

This usually happens when accessing the WP Toolkit section in "WHM / Plugins / WP Toolkit."

Workaround

This is a simple caching issue and should be resolve by running the following command: 

/scripts/rebuild_whm_chrome