I was not able to replicate this issue with your account. I have performed maintenance on your account that may correct this issue. If you still encounter problems there may be a problem with your browser. Please try the troubleshooting steps in this Yahoo Help article.
This error is on Yahoo's side. There is nothing you can do to fix it. You can try to contact Yahoo directly but do not expect a reply right away. They are aware of this problem and they are trying to fix it.
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I was not able to replicate this issue with your account. I have performed maintenance on your account that may correct this issue. If you still encounter problems there may be a problem with your browser. Please try the troubleshooting steps in this Yahoo Help article.
Fixing common problems in Yahoo Mail: http://help.yahoo.com/kb/index?page=content&id=SLN...
This error is on Yahoo's side. There is nothing you can do to fix it. You can try to contact Yahoo directly but do not expect a reply right away. They are aware of this problem and they are trying to fix it.
http://io.help.yahoo.com/contact/index?locale=en_U...
For product, select 'Mail'
For version, select how you access Yahoo Mail
For category, select 'Errors'
For sub-category, select 'received temporary error code'
Briefly tell Yahoo how they can help by typing the error message 'Temporary error: ymws:Server.MailboxOpenFailed' in the space provided
Scroll down and click Email a Support Agent.