Unable to download files from CC on-line storage

I'm trying to deliver images to a client but the links CC makes produce this error:

{"error_code":"401013","message":"Oauth token is not valid"}

I'm having to use a free drop DropBox device to get around this issue immediately.

Does anybody have a solution?

I tried to find my way through Adobe's help panel to get to chat with someone but they don't seem to have an option to talk about CC file storage or indeed anything relating to the CC all itself!

Thank you in advance.

Carl