ERROR: The requested URL could not be retrieved

# ERROR

## The requested URL could not be retrieved

While trying to retrieve the URL: %U

The following error was encountered:

- Invalid URL

Some aspect of the requested URL is incorrect. Possible problems:

- Missing or incorrect access protocol (should be `http://'' or similar)
- Missing hostname
- Illegal double-escape in the URL-Path
- Illegal character in hostname; underscores are not allowed

Your cache administrator is %w.