Big screen casting is life! If you've set up your Chromecast already, but can't connect, there are a few little things to try to get Neon casting.
Try disconnecting Neon from Chromecast by using the ‘disconnect’ button on the Chromecast menu. After this, re-connect and try watching again.
Make sure the device you're using for casting is on the same WiFi network as the Chromecast. (When using Chromecast you'll be casting from your mobile, tablet or a computer using the Google Chrome browser).
Try casting from a different site (such as YouTube or a TV on demand site) just to make sure the problem isn’t affecting that one TV show or movie you’re trying to watch on Neon. Close and re-open the Neon app from the device you’re using to cast.
Turn your router off and then on again. Also, take a look at the router settings and see if changing the WiFi channel does the trick. Your neighbour's WiFi can interfere if their router is broadcasting on the same channel as yours. Other things around the house such as microwaves, cordless phones or thick walls can also interfere with your WiFi.
Chromecast 1 (the older version) only works on a 2.4GHz wireless network, whereas Chromecast 2 and above will work on both 2.4 and 5GHz. If your router is capable of broadcasting both, make sure you connect to the 2.4GHz network if yours is the Chromecast 1.
If you've checked the above and it's still not working for you, give the Google Chromecast troubleshooting wizard a go.