After logging in the first time, you are directed to read and accept the Terms and Conditions of Use (for both MoodleRooms and Mahara e-portfolio). The agreements open up in a scrollable view.

Scroll down and click Seuraava/Next. Note that there are three pages altogether. 

On the third page you'll have to tick the boxes and then click on Seuraava/Next. If you click Peruuta/Cancel, the system logs you out and won't let you continue. You may log in again, but using Moodle further is denied until you accept the terms and conditions.

After clicking Next, the front page opens up. Now you've successfully logged in!