If your Roku device is not able to connect with your home router or gain access to the internet through the router, you may unable to build up your device. Cases, where the internet connection is lost after your device is set up; you may unable to launch channels that require internet connection. Otherwise, you might experience interruptions when streaming.
Go to : Roku not connecting to Wi-fi | go.roku.com/connectivity
For more information go to Roku Support.