Using an m600, I flew a nice mission using the UGCS beta app (android). However following landing UGCS disconnected from the drone, and I was not able to get it to connect again. I restarted the app a few times, turned off UGCS on my PC and restarted. The drone was in good health as I checked via DJI Go. I'm guessing the solution would have been to turn off everything and start over?
On another note, it would be great if the UGCS Android App displayed telemetry (location) information as well. Perhaps it does, but I couldn't find it. I was thinking, what would happen if my PC battery died and I was BVLOS? I would have to either hope it continued the mission successfully, or press the return to home button with no idea where it was (unless I opened DJI Go I guess).
Logs can be found in the following locations:
C:\Users\ [USER NAME]\AppData\Local\UGCS\logs
Android device (if you use UgCS for DJI app)
Device storage > Android > data > com.ugcs.android.vsm.dji > files > log_cat
Mac OS X
Please collect them and send to email@example.com
From my personal experience most probably cause is a DJI GO - if you started this app after landing it can get access to port and to connect UgCS again you will need to remove both apps from device's memory and reconnect USB cable.