We tried the below steps and were unable to reproduce the issue:
Install build 50.0.2661.95 and 49.0.2564.104
Sign-in to chrome and sync the data
Sign-out of chrome
Upgrade build to 51.0.2704.64
Sign-in to chrome again

Please let us know if there are any specific steps to reproduce.

It is good to mention that the error message chromesigninerror -206 seen in this issue is similar to the one reported in 602789 while testing MDM which is not in Stable yet. The root cause might be the same.

Based on the error, here is what I can guess.

The error happened while trying to fetch the managing domain of the address, which is the first time during the sign-in process when an actually valid account is needed.

This can mean several thing:
* This shouldn't affect @gmail.com accounts (we know for sure they don't have a managing domain).
* This might be a network issue (especially if the error took some time to manifest), but as it happens all the time, I doubt it.
* The most likely culprit is that the account is in an invalid state on the device (this could happen if you change your password). Note that we should have some things in place to detect this, but we might have a bug there.
* If signed in to other Google apps on the device with the SAME account, they should be affected as well.

Here is a way to fix this:
1. Go to the Settings, tap on the your account, then tap on your account again.
2. Tap on the "Remove account" button. The account will be removed from all the Google apps on the device.
3. Tap on "Sign in" and re-add your account to Chrome.
4. If prompted with "Import Data?", choose "Import existing data" and tap "Continue".
5. Everything should work correctly now.

Note: You'll have to sign back in on the other Google apps as well (without re-entering your password though).

Do we want to provide this instruction somewhere? Are users reporting this in the forum? Does this resolve their issue?

We've provided the steps to users in the forum and are waiting for their response. Thanks!

User has reported back that the sign in error still occurs after trying those steps. Please see this user's full response through this link: https://productforums.google.com/d/msg/chrome/SZQ1fikpDmA/dZxIqdcIAQAJ

Thanks.

I tried signing with the dasher account (test1@tomluc.mygbiz.com), but not able to reproduce.
I was able to sign-in to chrome on fresh install and on upgrade from M50 to M51 build.

I cannot reproduce either using what I think is the specific kind of account that the user reported (already existing non-google mail address).

I'll try to figure out if I'm testing with the correct type of account and check again.

Which version(s) of iOS is this issue occurring? We have seen some issues regarding sign-in with 9.3 and 9.3.1.

Given the symptoms, this has nothing to do with the sign-in issues we have seen with 9.3 and 9.3.1.

User reported back that he's using 9.3.2. There is another user reports back having this sign in issue with a non-google email account. 
Forum link: https://productforums.google.com/d/msg/chrome/SZQ1fikpDmA/w0by_cN6AQAJ

Thanks

I need to sync my chrome bookmarks from my hp laptop to my ipad.  keep getting the 206 error when I try to sign-in from my ipad.  have deleted and reinstalled chrome app, removed account access for the ipad, disconnected google account from google chrome, signed out and closed everything before restarting.  nothing works.  please help!

same error on iPhone, have removed and reinstalled the app. this error happens when signing in with non gmail account. is there a fix? please help

If I read the code correctly, you should see a spinner for about 10 seconds before this error is shown. Basically, Chrome needs to fetch some information of the account (if the account is non-gmail) before we can proceed with the sign-in.

1. Do you see a spinner for about 10 seconds before observing this error?
2. Do you have network when you're trying to sign-in to Chrome? If so, what connectivity do you have (how much time does it take for you to load www.google.com for example on this phone?)

Hi 
1. Yes i see the spinner for about 7 seconds and the error 206 popsup
2. yes i have full 4G network on the phone, google page loading is instant. i used someone else gmail account and that works without any error.
hope this helps, let me know if you need any more information

I have the same issue.  When I try to login to my account, the spinner shows up for 2-3 seconds then I get the 206 error.  I am connected to my home wifi and www.google.com loads very fast.

I have the same issue.

In my case, this started when I changed my Google account password (on my PC).

Unlike on my PCs, where I had a message in Chrome that my password had changed and I simply entered the new password, I found that I was automatically signed out of Chrome on my iPad after the password change and when trying to sign back in with the new password, the issues started.

My Google account is non-Gmail.

For me at least, this is more of a sync issue, rather than a sign-in issue. If I sign in to Chrome on the iPad with a different account (in my test, also a non-Gmail account), it works and I can switch on sync for this account. 

I can then ADD the Google account to Chrome with the "ChromeSignInError -206" issue and there is no error - the account is signed in. 

I only receive the message when I try to switch the account to sync with to the one that had the password changed and it always fails.

As with most people in this thread, I have tried all the suggestions:

- uninstalled Chrome, re-installed
- removed all Google accounts from the iPad (in Chrome, Maps, Photos, etc.)
- reset sync on Google account
- etc.

I have no problem signing in with this account on other devices and syncing. 

If I could be sure that resetting my Ipad and setting it up from scratch would fix this, I would do it, but for me, it's a huge amount of time to get everything installed and configured again, so I dont want to do this and then find that the issue is on the Google side and I still have the same problem.

So I too am a non gmail acct. I have chrome on lap tops and Iphone 6. When purchased the Ipad 6 have not been able to sign into chrome on it, same 206 error. Not sure if this is related but, I recently tried to update my phone number on my lap top to my Ipad phone number, just curious if that may be part of it... When i went to get a confirmation code, nothing came, tried twice, waited 5min and still no code. I don't know if the phone number, which is on my ATT account and active but not my primary is not being recognized by google sign in. Reverted back to my same number but still can't sign myself into chrome on the ipad. Tried all the above troubleshooting as well. Thanks!

Come to think of it, my google 2-step verification codes have never shown up on my Ipad like all my other sms or ims do, as the phone and ipad should sync.

My issue has now been resolved and it was a simple fix.

My Google account (non-Gmail) was configured with my e-mail address as my name. After updating my account profile with a first name and last name, the "ChromeSignInError -206" issue on my iPad was immediately resolved and I now have Chrome signed in and bookmarks, etc. syncing properly.

After a frustrating week trying to fix this, it is good to have everything working again. If only Chrome on IOS would have more helpful error messages....!!

Thank you, Rina. This is quite useful and will help us track it down. 

If other folks on the bug could follow the workaround in comment #23 and see if it fixes the issue and confirm, it will also help us narrow down the issue.

Thanks.

Yes, indeed, the workaround in #23 fixes the issue for me.

Thank you, Rina.

Can confirm - had this issue - Comment 23 fixes the issue

Yes - comment #23 fixed issue (non-Gmail email)

Note: Name needed to be updated/set in web (https://myaccount.google.com/)
It did not work when I first set name in Chrome app on my PC (I would expect my name to sync to the web from the PC app setup - maybe there is a slow delay in sync).

YES!!  Comment 23 is the answer for non-gmail iOS accounts!!  I can now log into my account on all iOS devices!  Note that non-iOS devices were not affected by this issue.

I've got the same error today on iOS 10.0.2 with a non-Gmail account.
I never used Chrome on iOS before, only on Win and Mac.
The workaround in comment 23 fixed it.
Other methods like reinstall the Chrome app, remove the Google account from the iOS device, disconnect the Google account in every other Chrome installation did not work out.
While receiving the error I sporadic received mails from Google informing me about new sign ins from Chrome on iPhone.
Before setting the name in my Google account it was my (login) email address.

My experiences were the same as #29.

I've filed the following bug for tracking: b/32468091

Same as #29.  My 'name' was my email address (non-GMail).  I didn't even realise this.  After reading this page I tried changing to my first name and surname.  Bingo, Chrome on IOS logs in fine now.  Thanks!

Thanks #23 fixed my issue also

Bulk edit: not working on Chrome anymore, re-assigning to the current Signin iOS owner.

Like so many others have said.....post number 23 worked for me. 

Yep, non-gmail account had to change First Name and Last Name to something other than the non-gmail address. Fixed it. Is someone working on this bug? Seems to have been going on for a long time.

 Issue 722078  has been merged into this issue.

CC+ chaowei@

After a while trying various fixes to get Chrome to sign in I too can confirm the workaround posted almost a year ago fixes this (comment 23) to go into the Google settings page and enter a first and last name. Thanks for the help!

It would appear this bug was introduced with version 51 and we are now up to version 59. Is a fix still being worked on?

Robin

We cannot reproduce this bug (tried again in June 2017) - it looks like this may be related to old non-gmail accounts and we cannot find/create an account that we can use to test this bug.

I guess this issue can be closed as cannot reproduce. But if someone report it again with the new error message from  issue 749699 , we will be able to investigate more.

Let's close this as fixed given the update of increased quota in dependent services at https://bugs.chromium.org/p/chromium/issues/detail?id=749141#c21.

But please feel free to update this bug with any new instances of this issue occurring.

This happened on IOS 10.3.2.  Like the other comments, you have to change your Google account name to something other than your (non-gmail) email address.  Once I did this, Chrome started working.

Same issue on iPhone X and iOS 11.2.1. Comment 23 fixed my issue. This article was the only thing I could find even relating to the issue error 206. I use a non gmail account for my Google account. Changing my name in my account preferences from my non gmail address to my actual first name and last name immediately rectified this issue. 

My issue is the same comment 23 and 52, and now I have fixed it after adding my name.