This usually means the URL inside your config.txt is dead or offline. Hosting these databases can be legally grey or expensive to host; links change frequently. You will need to find updated links from active community forums.
: If you're feeling adventurous, you might try creating or editing a config.txt file based on your best guesses. However, be cautious and back up your data before making changes.
, telling the system exactly where to fetch its data. Its "top solid feature" is the ability to of .pkg files from external databases without needing a PC. Core Functionality of config.txt