1. Check your Smart TV model to ensure it supports the desired streaming service or app.

2. Make sure your Smart TV or streaming device is connected to the internet with an active network connection.

3. Update any firmware or software that may be needed for the app to run on the TV or the device connected to it. This could require checking the manufacturer’s website for any available updates.

4. If you’re using a streaming device, make sure the correct input is selected on your TV.

5. If all else fails, try uninstalling and reinstalling the app or service if possible.