My two cents work is betting that it's a Crave issue. On my most recent call back to Crave they asked me to do a few screen shots from a few "debug" URLs. So I sent that information back and we will see where that leads.
I just signed in to crave.ca/apple and entered the 7 digit code the same as I have every night for the past couple of weeks lol. This time when I entered the code.. it hesitated for half a second then went to the crave home page. I continued the sign in process on my iPad. I was shocked not to see that big red grammatically incorrect fail lol.
I contacted Apple and they tried to help but they had nothing in their documentation that could fix the issue. They said it must be a Crave App problem.
I tried to get mine to work and it did not....did you reset your Apple TV....i have tried it 4 times with the same message.