I was trying a first test Mission which involved about 45 photos. However, when I tried to download the photos to my computer, there were none. I powered up the drone and controller in my office and there neither video or stills were displayed. This required a lot of experimentation, and I finally decided that it was not a problem of transmission, but rather that the camera was not generating an image. I then decided it must have been a faulty firmware upgrade. So I followed the procedure for upgrade using the SD card. After doing this, and restarting the controller and drone, all was well. I am convinced that I somehow fouled up an earlier upgrade attempt.