First post on the DJI forum. Purchased a Matrice 600 Pro and have been fully impressed with the minimal assembly, pretty much flew out of the box. Dealing with the App and Assistant was not as intuitive...but videos can be found to help with most issues. I'm now trying to download the .dat files and manipuate them to save in csv etc.  Mainly I need the GPS data. Anyway, I get to the Flight Data screen where I have two options: Open Data Viewer and Enter SD Card Mode. The latter works but not the Viewer. I checked the Assistant and found no viewer.exe file. Why didn't this download with the Assistant? Or is it a separate download? Can't find it on the DJI website. Thanks

Depending on the M600 you have DatCon could provide what you need.

http://datfile.net/DatCon/intro.html