@Stevechedgzoy welcome to the forum!
You are refering to http://demo.openpetra.org/
You should be able to login with user demo and password demo.
Just ignore the alert about the expired session.
You should be able to see the menu.
There is currently no real functionality implemented.
We are restarting the development of the client, by writing a client in the webbrowser, because the winforms client is not portable and only supported Windows.