A change of Wifi network necessitated that the same be changed for a working chromecast device. When the chromecast was reconfigured using the Google Home app, it would not communicate with the new Wifi network. An error message was printed and the configuration session would end.
The problem was solved by doing a hardware factory reset on the chromecast device. For reset, as well as for further configuration, the chromecast device needs to be powered on and connected to an HDMI port of a TV and the TV display should show the chromecast output. The hardware reset button is at the circumference of the chromecast device.
Google chromecast reset button
Keep the reset button pressed for about twenty seconds so that hardware factory reset is done. After that, follow the configuration procedure from the Google Home app running on a mobile device.