Cubecart admin and customer login | Hosting issue?

Hi, I have a cubecart online store, that I put together for my wife. It was running great then all of a sudden the admin login and customer login stopped working. When Logging in It gives you a "Forbidden You don't have permission to access /[login to view URL] on this server. Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request." It's got to be something simple, with the hosting. I can't imagine anything has changed since it was working great a day ago. Don't have time to fix this issue. But need to fix it TODAY... Like RIGHT NOW.