Without explaining the error, I am 90% sure I know what you are talking about. I run a NY forum and I was just thinking about making a thread about the yahoo error that I think you are referring to minutes before I saw your question here.
If you look directly above the error message, you will notice that it says advertisement. It is not a real error but an advertisement that they are trying to get you to click. In my opinion it is sheisty advertising making people think they have something wrong with their computer or connection.
If you are talking about something different, please give more details. What does the error say? If this is what you meant, please take a moment to let us know that we have answered your question. Thanks!