Apple TV is stuck in a endless loop of signing into your itunes account...
If your Apple TV is stuck in a endless loop of signing into your itunes account (in other words, forcing you to enter your itunes ID, then password, then a 6 digit verification code, then returning you right back to enter your itunes ID again, AND AGAIN AND AGAIN!)... here is the solution:
A) From an iPhone / iPad, go to ‘Settings’ => ‘Apple ID, iCloud, iTunes & App Store’
B) => ‘Password & Security’ =>’Get Verification Code’,
Now make note of the code or leave it displayed on your phone for reference.
C) on your Apple TV, go back to the troublesome iTunes login again and enter your itunes login ID.
Click ‘Submit’
D) you should now be on the ‘enter password’ screen.
Enter your password and append the verification code to the end of your password.
For example: if your password is ‘MyApple’ and the verification code is ‘121454’ , you would enter:
MyApple121454
E) click the ‘Submit’ button and your problem should be solved.
The Apple TV main menu will be displayed indicating that your itunes login was successful.