This error means that the charger cannot connect to the WiFi. It might happen for many reasons, such as a wrong password or the connection is too weak to sustain.
The first thing is to connect your phone to the local WiFi to ensure that a connection is possible. In large commercial installations, company's network router will require certain ports to be open. (This is also true of home installations, but in those cases the ports are usually open already).
For more information on requirements and how to add a new WiFi, see WiFi Connections.