The web-based MINDSTORMS 3D Building Instructions are not supported by all browsers, as it uses WebGL Technology. Please check below for the browsers support levels.
Fully Supported - Chrome (from version 18) and Opera (from version 15).
Partially Supported - Safari and Firefox. If you experience problems with these browsers it may help to update your video drivers.
Not Supported - Internet explorer
Remember, you can download the 3D Builder as an App for your tablet smart device.