The above dialog from Ableton Live means that you need to install MaxforLive.
MaxforLive is available as part of Live Suite or as a separate upgrade to Live Standard, you will be able to purchase it directly via your account at Ableton.com
If the above content doesn’t answer your pre-sales query then please use the contact option in the main menu on the left.
If however your looking for support on your existing purchase please head over to your account and submit a support ticket from there to prioritise your response time.