Hi, Try Updating the Internet Browser you are using at the moment or using a different Internet Browser.
Or Contact Yahoo by Email, this can be done by clicking on HELP at the Bottom Right Hand side of the Yahoo Home Page under Horoscopes.
Click on whatever Subject is best for you for more information, you can also Click on the Arrows for more options, or Type your Problem in the Search Help box.
You can also Go to the Right hand side of page and click on Contact Customer Care.
Click on Category, page will reload for you to click on Sub Category.
Make sure you fill in Brief Details of what has Happened, click Enter.
Depending on the Category you select and the Sub Category you also select you should then see at the Bottom of the Page for more help Click on EMAIL A SUPPORT AGENT. You may have to click on different ones and try variations.
There will then be a Form to fill in. Fill in the form with as much information as you can remember about your security details and your account.
Yahoo will then contact you at a Different Email Address that you need to give them. This email address CANNOT be a yahoo email one.
You need to give them a different Email Address, it could be one that you already have or you will need to create a new one, Google, Hotmail, etc. You do this by clicking on Email and then click on Register and follow the instructions.
They only need this Different Email Address to give you instructions regarding your yahoo account.
When Yahoo send you an email, make sure you check the Trash and Spam folders as well as the Inbox in case it went in there instead.
You will be asked to create a New Password, Best a hard to Guess One for anyone trying to access your Yahoo Account.
I Would Also Strongly advise that you register an alternative email address and your Mobile Number/Cell Phone Number with Yahoo, that is done through Account Settings. (I Think).
That way if your account is ever hacked or similar, a message should come up and they can send a code to your phone or other email address for you to then unlock your Yahoo Email Account.