Wrong links in WordPress?

Go to Settings, then General Settings, then enter the correct url for your WordPress Address (URL). Perhaps you need to change your Site Address too.

Source: The WordPress Codex: http://codex.wordpress.org/Settings_General_Screen

If this isn’t the case, but the category links are bad, edit the category slug. Go to Posts, then Categories, select article and edit the slug. Perhaps you had a different slug beforehand.

It’s difficult to help you. It’s a game of guessing. I will stop here.