An Advantage 6420 error occurs when the client application is unable to connect to the Advantage service on the server. Advantage will normally use a discovery process to connect. The Advantage ADS.INI file was developed as a solution for when there are problems with the discovery process. This document details the most common steps to resolve an Advantage 6420 error. It is written at a low level so that people without a lot of technical ability should be able to follow along.