Can't sign in to xbox live on 360, or play live 360 games on xbox one

I can't sign in to Xbox live on 360.

I can sign in on my Xbox One, but if I choose 360 games on my Xbox one it says the same. But Xbox One games works fine?

Same here, it happen to me can't sign in to 360 on the xbox x to play 360 games, hope they get their s it together.

Got to xbox to play 360 games and 2 live memberships and can't even play, wasted of money

According to Xbox Live Support:
"You can be signed in to one Xbox One console and one Xbox 360 console at the same time. However, there are some apps that you can't use on different consoles at the same time."

My question is: What if I play a Backwards Compatible 360 game on the Xbox One, will it log me off the Xbox 360?

Hardware wise, it can't be done to link an xbox one to the 360. However, if the game you want to play is backwards compatible, it could link up to the 360 game in the 360 through Xbox live. Offline and without Xbox live, it won't work.

Thanks for your help, but neither works. As i say its just stuff pertaining to the Xbox 360. I can play 360 games on the Xbox 360 and the Xbox one, but can't do multiplayer or access 360 DLC, though I can play 360 games that i've downloaded. I can be connected to Xbox Live on the Xbox one, but as soon as i try to play a 360 games I am disconnected It's most frustrating as one can't speak/use chat directly to Microsoft regarding the issue.