pictures or videos (can't tell which) in lessons

just signed up and they aren't showing up ... instead I get a blank box with a red "x" in the upper left hand corner.

Hi there, thank you for your post on the Rocket Sign Language Forum. We apologize for the trouble you have had with the pictures/videos files. I passed the issue to our technical support and the problem has been fixed. Please go back and try again. We apologize if this has caused any inconvenience. If you continue to have problems, please let me know. All the best for your Sign Language learning!

they are videos

If I may add, very well done videos.