An app that won't launch at all is a different problem from one that opens and then misbehaves — here's where to start.
When an app doesn't launch at all — nothing happens when you select it — the cause is usually different from an app that opens but then crashes or freezes.
Uninstalling and reinstalling the app is the next step — see our guide on resetting a streaming app that's not working for the full process.
That points to the device itself rather than one specific app — see our guide on signs it's time to upgrade your streaming device, or contact support for further help.
Compare subscription options and device support to find the plan that fits your household.