There are two scams here. One is the poster of the question who claims to be having difficulty. If you mouse over the avatar they are typically level one posters. The second are the answers encouraging users to contact the 800, 844, 855, etc., numbers. They may be even the same person using various accounts. All of these numbers are off shore scam sites. Give them access to your computer (they will check out your problem remotely) and you're held hostage. We all experience periodic difficulty in logging-in to any website. Just don't fall for the scams. Typically, just exiting the browser and relaunching it will resolve the problem. I've even had to reboot my computer and that solved the difficulty.
A friend of mine was having difficulty with his computer on AOL (same idea) and fell for the scam. His credit card was charged several times and he has no idea what files on his drive were viewed and copied. It's up to Yahoo to delete these accounts or to give trusted users the capability to do so. Unfortunately, the present situation at Yahoo seems to leave a gaping hole in this problem.