I was getting the same thing last night and it freaked me the hell out.
I decided to restore my account last night. All I did was recover / add my XDC account to the Guarda web wallet (https://guarda.co/app) and used my secret key to interact with my funds there. Everything seems to work great there and after some of the other issues people were having with Xinfins web wallet, I think I will stick to using Guarda for now.