The camera connector is facing the right way (metal bits facing HDMI port) and is properly in the socket.
I’ve double checked the connections and now ./arducamstill -? lists all the available formats. However, if I try to take a picture or use ./preview-dualcam, I either get “init camera status = 4100” or a timeout.
“./camera_i2c” still doesn’t show any connections. I checked /boot/config.txt and the required lines are there.
I had the same problem. I am not sure whether this thread is closed or still open. Regardless, I just want to say that I solved this problem by enabling the legacy camera support in raspi-config and adding start_x=1 in config.txt. Since the legacy camera needs mmal libraries, enabling it would resolve this issue.
So, if you are able to access a single camera through raspistill or raspivid, then you should be able to install the MIPI driver.