This issue would be a disaster for me it there wasn't a workaround that I've discovered. I got the impression from Rush tutorials that inserting other media - stills, graphics, etc - was no problem (inserting isn't a problem, actually, BUT then . . .) but then when I went to export the workflow, which I've been working with for several weeks and including about 50 stills, none of the stills were visible in the exported mp4. Imagine my panic and shock! I have found a work-around, though, which is that I transferred my workflow to Premiere Pro, and that delivers everything in the final product as expected, so I am tremendously relieved. I hope Adobe's engineers are catching this, because it's a real shortcoming in Rush, and something that I automatically expected in that otherwise very pleasing program. I hope that this helps you, too!