Message: Failed to delete source string because deprecating the key match files failed.
Cause: Deleting a key match source failed because an error occurred while trying to deprecate the source's key match files by moving them to a different directory.
Solution: Examine other error messages for an indication of what error occurred while attempting the move. Key match files are moved to a temporary directory ('tmp') in your Watson™ Explorer Engine installation directory prior to deleting a source. Make sure that this directory exists and that the web server can write to the specified directory.