Today, I faced the same problem. My applications are filled out and sent to KCC already but I wanted to review the applications for any possible mistakes and got the exact same message. I thought it is because my application is locked and it does not read my CN (though I opened it few times after submission) but it seems there is some problem with the CEAC system. I guess, there is nothing to worry about, contact KCC and ask when the problem will be solved to finish submission.
Soffione got a reaction from Eshetu in DS-260 login page