Go to the Google Home app’s Devices section on the streaming device and check whether the Chromecast is listed. If it is not listed, it means that the Chromecast is connected to a different Wi-Fi SSID. Reconfigure the Chromecast so that it is connected to the same Wi-Fi SSID to which the iOS device is connected.
If the error code 40102 hasn’t been cleared, check whether you have configured a service such as VPN or proxy which redirects the internet traffic to a different region. If you are using such a service, it could cause the Netflix Error 40102. Disable this service and then check whether the error code is cleared. If your ISP has provided an IPv4 network, you need to change it to an IPv6 network because Netflix does not support IPv4 networks.
Power off the iOS device, modem, and router. Detach the power cables from these devices. Wait for at least one minute before reattaching their power cables and then power them on. Now, the error code 40102 will be cleared. If it persists, you can contact our tech support team to clear the error code.