Your choice to follow their upgrade or just put up with the nags.
The error/nag message here noted account SETTINGS. But that's not noted in your post.
https://forums.yahoo.net/t5/Manage-your-account-settings/Account-Settings-are-out-of-date/td-p/37661 is about that message but some claim the usual does not clear it up. Other reasons are malware and overzealous antivirus suites.
Since the cause is all over the map, using only what you supplied will not result in a do this answer. Frustrating for most, this is typical of PC issues. We must be sure that our PC is in a condition Yahoo expected. No malware and no odd protection software.
Read what Grif advises on Malware detection and removal at http://www.cnet.com/forums/discussions/how-to-remove-pup-option-603542/#post-f742c795-5881-433b-a29b-6d758efe5cd3
I am not sure if this question is in the right forum ! I posted this in an other Forum and got a response. It did not solve the issue.
I use Yahoo for emails, I have been using it for years. Recently in my new computer (6 months old )I have started getting ,"your account is out of date" messages. I have tried using different browsers but the problem persists. I will be grateful for a solution.

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