1. Confirm your TV model is compatible to download apps or services in the app store.
2. Ensure you have a good and fast internet connection.
3. If connected to a router, restart that router.
4. Check the DNS settings on your TV to ensure they are correct.
5. Check for any software updates, particularly for the built-in app store, if available.
6. Contact the TV manufacturer’s customer service if the problem persists.