The only solution is to sign into your YouTube channel's linked Google+ Page directly, with the Page's username and password.
If you recently chose a name for your channel from the "YouTube is updating your channel" prompt or otherwise linked your YouTube channel to a Google+ Page, there is a chance that when the linking process was complete, you were shown this error message and prevented from signing in to YouTube:
! Sorry we found some errors:This may not seem to make any sense, since there was indeed a YouTube channel that could be logged into - at least until the channel was linked to Google+.
• You are not eligible to create an account
• Sorry, your login was incorrect
When contacted, YouTube support usually provides an explanation along these lines:
The Support Team investigated your channel (channelname) and determined that the reason you're having trouble signing into the channel is because your email address is associated with an account that was previously terminated by YouTube. Once your account is terminated, you are not permitted to create new channels.YouTube's policy is clear:
An individual whose account has been terminated is prohibited from accessing, possessing or creating any other YouTube account.
Why does this happen?
When you link a YouTube channel to a Google+ Page, the YouTube channel is moved to the Google+ Page's special Google account. That frees up your original Google account - the one used to sign into your YouTube channel before linking to the Google+ Page - to create a new YouTube channel.
It's at that point that YouTube's systems may notice that the email you use to sign into your Google account was at one time associated with a terminated YouTube channel. That old YouTube channel could have been closed years ago, but that doesn't matter: you aren't allowed to create a new account.
How can you access your original YouTube channel?
So what happens to the channel that was linked to the Google+ Page? In the reports I've seen in the YouTube help forum, that channel is usually still up and running, even though there is no way to access it by logging in to YouTube with its original email username and password.
But there is a workaround: the original YouTube channel can be accessed by signing in to the Google+ Page it is linked to directly.
Note June 2014: see the updated instructions for setting a password for your Google+ Page
To create a password for your Google+ Page:
1. sign in to Google+ with your original email username and password
2. go to your Google+ "Your Pages" list by clicking on the Pages option in the left menu, or going directly to plus.google.com/dashboard
3. click the "Manage this Page" button under the name of the Page you created for your YouTube channel:
4. From your Google+ Page's dashboard, click "More" at the top of the page, and then "Settings":
Alternatively, click your Google+ Page's avatar in the upper right hand corner and select "Page settings":
5. On the Settings page scroll down to "Third-party tools" and click the "Set up a password" option
6. Add a password of your choice:
If you do not want to use the auto-generated @pages.plusgoogle.com username, you will be able to create a new Gmail email address.
You then should be able to use this username and password to sign in and manage your Google+ Page-linked YouTube channel.
If this has affected your YouTube channel, there are a few limitations you should keep in mind:
- you will not be able to unlink your YouTube channel from its Google+ Page
- you will not be able to delete the Google+ Page (or your entire Google+ account) if you want to keep the linked YouTube channel
- if your Google+ Page is owned by an account managed through Google Apps, or by a Google+ Profile for someone younger than 18, you won't have the option to set a Page-specific password.
If those instructions aren't clear, check out this video tutorial:
While it's not an ideal way to manage your YouTube channel, it's better than the alternative, which is not having access to it at all.
YouTube Help: My YouTube account was terminated
A: How to deal with the Not Eligible To Create An Account & Login Is Incorrect Errors
Google My Business Help: Set up a password for your page