This is likely due to a slow or low quality SD card being used. Make sure you use genuine U3 cards or slow down the imaging speed to Class 10 (3 seconds) in the settings menu.
The issue with the video feed dropping out can also be due to what John noted above: processor performance. Map Pilot is doing a lot of stuff and older process have hard time keeping up. We highly recommend using the iPhone 6 and up.
16kb images are due to a hardware failure in the camera or buffer issue.