verification failed

"verification failed the application you have selected does not exist." yes my password is correct. I keep getting this error message when trying to sign into my apple ID on my iPhone 10, Icloud and Itunes on my computer. It was working earlier but now it isnt. Hopefully its a system issue and not that someone tried to hack into my account. Glad I'm not the only one having issues with this today I didnt even do an update so this is really stupid.