1 - Turn off Wifi using the button;
2 - Open the browser and go into Browser Settings scroll all the way down and Clear All Data;
3 - Keep wifi off and open the QR Code;
4 - Go trough all the Next windows and choose Google;
5 - After it says Connection Error close the browser turn on Wifi with the Button and go into the Browser;
Make sure you are on a Fast connection I realized if your on bad wifi it will always fail.
Also make sure you actually have the boot.3dsx file/starter kit in your SD Card otherwise it will always fail on Gray screen.
If it still fails let me know ill let you know another Method.