If you experience the error code R8102-101 on your Xbox 360, it typically indicates that your Netflix app is out of date. Follow the troubleshooting steps below to resolve the issue.
Begin from the Xbox Dashboard.
Navigate to Apps.
Select My Apps.
Highlight the Netflix app.
Press the X button for app details.
Press Yes to confirm.
From the Xbox 360 Dashboard, navigate to Apps.
Select the Netflix tile to begin downloading the app.
Once the download is complete, sign back in and try Netflix again.