yahoo website and unable to check for updates

i have no idea if these are related, but one day my yahoo mail app started not working, and i tried to log out and log back in, but when i tried to log in, the website said "Safari can't open the page because the address is invalid." then today, i tried to check for an update, and it didnt work. it said, "Unable to check for update. An error occurred while checking for a software update." i dont know whats wrong but its not working