Did you make sure to type in a name at the top?
Yes, I was able to create media a couple days ago (Haven't played the two small updates yet though). It took me about 5 minutes to see that there was a name required at the top for media (I kept thinking I was missing some research option). It seems this can easily be missed with media as with a single you have to name it before you do anything else. With media your attention is immediately taken to all the options and then you are looking at the bottom right wondering why you can't continue when you forgot to type a name at the top left. The setup should probably be similar to a single or have a hover if you put your cursor over continue saying what you are missing.