I am using Tobii Studio 1.1 and at startup it asks for a license key.

You need to upgrade to version 1.2 or higher. There is no cost. Please contact your nearest Noldus support office or Tobii to obtain this upgrade.

The Observer XT, The Observer XT 6, The Observer XT 7, The Observer XT 8, The Observer XT 9, The Observer XT 10