The technology for the website is quite new, so if you are having minor issues do not be discouraged. Most issues can be solved by switching to Google Chrome, I don't know why but it works a lot better for this site than other browsers. Please also clear your cache (press ctrl+F5), this is often a problem even after fixes have been made.
If the learning interface is not working correctly, switch to Chrome, or, wait a while and it will probably be fixed soon (make sure to clear your cache).
Sorry for the inconvenience, its all a work in progress.
Which software are you using for 3d-knowledge.com?
A mixture of Blender and Solidworks.