Your browser does not seem to support JavaScript. As a result, your viewing experience will be diminished, and you have been placed in read-only mode.
Please download a browser that supports JavaScript, or enable it if it's disabled (i.e. NoScript).
So you can login now? I don't know exactly where your problem comes from.
You should have two mandants, one for german and one for english language. They are selectable directly after the login page.