can't connect iCloud account in Apple TV

It seems this is a new error message for an known situation:

If you have Two-Factor Authentication for your Apple ID, and an older device, then the sign-in procedure is a bit special:

What if I use two-factor authentication on a device running older software?

If you use two-factor authentication with devices running older OS versions—like an Apple TV (2nd or 3rd generation)—you might be asked to add your six-digit verification code to the end of your password when signing in. Get your verification code* from a trusted device running iOS 9 and later or OS X El Capitan and later, or have it sent to your trusted phone number. Then type your password followed by the six-digit verification code directly into the password field.

There is a time limit before the code expires, so it is best to request your code (or a new code*) after entering the characters of your password, to use those precious seconds effectively for just the code.

If you are trying to enter the password and code together then that will easily exceed the limit. This will result in an error or it will loop back. You need to enter the password only, then request the code, and then add it to the end of the password.

The key points on this for me are:

1. If you can login without having the code visible, awesome! Go with it, and post about it here!
2. But I couldn't login without having the code visible, so I wanted to share that tidbit to potentially take one challenge out of the equation for people.
3. There's no downside to keeping the 6-digit code visible on the device displaying it while you enter it and submit it on your Apple TV and while Apple subsequently validates it, and since following that approach made all the difference for me and, although they didn't necessarily identify it the same way, I believe it's made all the difference for some others, I argue there's no reason not to try it.

The reason it didn't help you is that you weren't trying to accomplish what I was trying to accomplish. I was trying to get logged for iCloud Photo Sharing. You indicated you're trying to get Home Sharing to work. I can't get that one to work either. Check out the discussion at https://discussions.apple.com/thread/250592472 and you'll see that it's widely acknowledged there that at this time there is no way to successfully login to Home Sharing on an Apple TV 3rd generation using an Apple ID with 2-factor authentication enabled. So unfortunately, neither my approach nor anything else is going to do the trick for you at this time.

That's interesting that you get the same number upon multiple requests for a code on your device. I didn't know it worked that way.

It may take too long if you get the code before entering the password. Therefore get a new code after entering the password (do not submit yet), then add that code to the end of the password, then submit.

Not intuitive, but documented: HT204915, Two-factor authentication for Apple ID

"What if I use two-factor authentication on a device running older software?

If you use two-factor authentication with devices running older OS versions—like an Apple TV (2nd or 3rd generation)—you might be asked to add your six-digit verification code to the end of your password when signing in. Get your verification code from a trusted device running iOS 9 and later or OS X El Capitan and later, or have it sent to your trusted phone number. Then type your password followed by the six-digit verification code directly into the password field."

I'd agree with @jmuelhaupt

"you might be asked to add your six-digit verification code to the end of your password when signing in"

but he/she wasn't and this response implies they never would be

"when using an older device you aren't going to be prompted for the code and need to add it to the password instead"

Also I even went to www.apple.com/support/icloud, as suggested on the TV image, to see if there was something glaringly obvious about sign in issues and there's not and most options seem to take you, firstly, to Check iCloud services or make a call to apple support with the best option probably being Apple Communities but then it defaults to iCloud forums. So the link is actually pretty useless and they'd be better off stating something more useful than a generic error message imho.

That worked just fine. A huge thanks for providing solution.

I hope our friends at Apple read this and improve their instructions: When I entered just the password as usual, the instructions on Apple TV directed me to https://support.apple.com/icloud which provided no help at all.

Right: it's a known issue that at this time there is no way to get Home Sharing to work on 2nd and 3rd generation Apple TVs. See the thread at https://discussions.apple.com/thread/250592472 and feel free to pipe in there!

It depends on what you're trying to accomplish. If you want to get iCloud Photo Sharing to work, multiple of us have found that it can be done and if you read through this thread you'll see that I've listed out the series of steps I went through to get it to work. In regards to the piece about getting logged in, I found that it was key for me to have the code visible on the device presenting it all the way through entering it, submitting it, and having it validated by Apple. As discussed previously in this thread, this seems strange, but for me it was critical.

If, however, you're talking about Home Sharing, then check out https://discussions.apple.com/thread/250592472 where you'll see that it's a known issue that at this time there is no way to get Home Sharing to work on 2nd and 3rd generation Apple TVs.

I got the solution from another discussion!

1. Type in your Apple ID password in on the Apple TV
2. On another Apple device, go to Settings —> Apple ID —> Passwords & Security —> Get Verification Code
3. On the Apple TV, type in the 6-digit verification code at the end of your password

Ex: Mypersonalpassword334862

This time I'm bringing all good news, but with a caveat.

The good news: it appears that Apple has resolved the issue with being unable to access iCloud Photos (and it's possible it was also working at the time of my last post and I just didn't know how to "crack the code," so to speak; read on for more info).

The caveat: you have to go through (or at least I had to go through) a lot of gyrations to get there.

The gyrations:

1. First thing to note is that if you're already logged in, you're probably going to have to log out first. I was finding that in iCloud Photos, the albums would display but the actual photos in them would not. I was not able to figure out any way to resolve this (and yes, I tried rebooting) besides logging out and logging back in.
2. As I posted previously, logging into iCloud on the Apple TV 3rd generation now works the same as it does on other devices. You enter your Apple ID then your password and then you'll have to enter the code that will be displayed on one of the other devices on your account (when doing this, I continue to believe it's important that you not clear the code from the other device first, though I didn't test that this time). After you login, you'll need to go into iCloud Photos Settings; what I care about is iCloud Photo Sharing so in there I turned that on and I made sure Photo Stream was turned off, but you'll need to make whatever choice is right for your circumstance.
3. Immediately after logging in when I went to iCloud Photos and it gave me the "iCloud Unavailable" message. But after waiting several minutes and trying again, I got the "Loading iCloud Photos" message, but it just wouldn't clear.
4. So then I went back into Settings and turned off iCloud Photo Sharing.
5. Then I went back into iCloud Photos. Now, with nothing turned on in settings, it asked if I wanted to turn on iCloud Photos. So I said yes. And then, after telling it no, I didn't want to use Photo Stream as my screensaver, I had to login again. Why? No idea.
6. Then after I logged in, it still told me iCloud was unavailable and there was as problem with my password.
7. So then I tried again and then I got logged in and it took me into iCloud Photos showing My Photo Stream with 0 photos (and of course I have hundreds of photos in my Photo Stream). My shared albums were not displayed. So at least I was in, but it wasn't showing me any photos.
8. So then I went back into Settings and turned off iCloud Photo Sharing.
9. Then I turned iCloud Photo Sharing back on.
10. Then I waited several minutes.
11. Then I went back into iCloud Photos and there were my shared albums (with actual access to the photos, unlike in item #1 on this list).

It's possible these exact steps will not work for you. It's possible that you will have to go through even more gyrations to get this to work. It's also possible you will be able to go through less gyrations to get this to work. The point really is that this process is quite nutty and you have to stick with it and keep trying things.

It's rather frustrating. And to depress you even further, I've found that over the last few months iCloud Photos has frequently and randomly stopped working (that is to say, I've been logged in and able to access photos from a shared album and use them as a screensaver and then that just stops working). I've usually able to get things going again just by rebooting the Apple TVs and though what brought me here to this thread is that this time around that didn't work, hopefully going forward when this breaks again (and given how frequently it's broken in the past, I have to believe it's going to break again), a simple reboot will clear it up because I sure as heck don't want to go through all these gyrations on a regular basis.

2 factor authentication is optimized for newer software, when using an older device you aren't going to be prompted for the code and need to add it to the password instead (as documented in the article).

As there is a time limit for the code it is then recommended to request the code after entering the password so as to not exceed that limit. If those steps are not followed or the limit is exceeded then it will loop back or produce an error.

As stated above 2FA is optimized for newer software, in which one will enter the password and then be prompted to enter the code separately.

The article is merely stating that when using an older device you will need to add the code to the end of the password instead.

The error message is simply stating that it was unable to sign in, however if the link provided was found to be of no value then you can give that feedback to Apple

This isn’t working for me. I changed my Apple ID password a couple of days ago and haven’t been able to access iCloud on ATV3 since. I’ve added the 6 digit verification code after the password (it took about 9 seconds) and it just says it’s the wrong username or password.

Anything else to try??

What is the limit? I thought it was 30 seconds? I’m typing my password on the ATV, then requesting the verification code on my iPhone, adding the code to the end of my password, selecting ok on the phone and then submit on the ATV. From requesting the code to hitting submit is no more than 10 seconds.

If I just put in the password the ATV says “can’t connect to server”, if I add the verification code it says “wrong username or password”.