session code expired but why

Darkkhelmet

I have use the free version at home when necessary for many years. I built a new home PC a few days ago using Teamviewer for many things. Now that PC is my current PC and I am trying to help my wife with an issue on her laptop . My first attempt asked for the ID and then the password. When I entered the password after a short time I got the session code expired message. I have downloaded the latest versions on both computers. Now whenever I try and connect it just shows session code expired. Why, and how can I fix this?