I've looked for it and found it, with the same issue noted as above.
Seems to be a video that is still in review by OutSystems staff, before they 'unlock it for the public'.
Also...all video's within this course on 'Cross-platform', display this 'Private Video' message.
That being said, I recon that modeling data is just about the same for Windows only as it is for Cross-platform. Just open the Windows only version if you want to complete the course.
https://www.outsystems.com/training/lesson/1916/modeling-data
