I've got an M300 & M200 and have never had an issue with file transfers but on my first files on the mini 3 pro I can see the mp4 & jpg's on the Sandisk 400GB extreme pro but when I attempt to copy them over to my PC it drops the connection.  Literally the drive letter disappears.  I've tried a few PC's and Surface with same result.  What am I missing?  Thought about a convert from exFat to NTFS but I am afraid of messing them up and can't make an Xcopy either.  

Transfering from the aircraft? Card reader?

Sorry....from a Lexar card reader.

I had same issue.  if you formatted the card in the Drone, using the app... it doesn't work.. it's a corrupt filesystem.. I tried a few times and although I could see the files from the app, they wouldn't work from windows... sometimes the drive was recognized, other times it said I had to format, the few times it was recognized if I tried copying a file my system hung.  I lost all my first videos and did a reformat twice with the app... same issue.   I tried 4 different card readers and two PCs...

the fix for me was easy, format the card from windows... never had another issue for nearly a month now.

note: mine is a 512gb SD card, so maybe it's these large cards the DJI app is laying down corrupt file systems

I was afraid that was the answer.  I scaled the side of a mountain to get these shots.  My body can't do it again.  I will try many tools....hopefully not fully corrupt but this was formatted in drone which I normally do not do.  Painful!  

Have you tried transferring from the Drone itself?  I built a stand with multiple fans to keep the drone cooler while doing the transfer as the drone must be powered on before connecting the cable to transfer the files to a PC.  It may also be the type of card reader.  I have had strange things happen when mixing brands of cards and readers.

Huh, I've never experienced any of these issues with a DJI aircraft. I've always used SanDisk cards with SanDisk readers, or my windows PC's card slot.

I was able to get one off by transferring from the drone to ipad, its just god awful slow… apple isn’t friendly to any USB devices.   So the drone can somehow figure out the filesystem even though its corrupt.

KLRSKIR Posted at 7-15 13:08
Huh, I've never experienced any of these issues with a DJI aircraft. I've always used SanDisk cards with SanDisk readers, or my windows PC's card slot.

I agree to the Sandisk cards and readers.  I ran into problems years ago in my photography learning days and before I was introduced to Drones.

I can't get PC or Surface to copy over jpg or mp4 files but it lets the SRTs come.  I can see the damn thumbs of my photos and vids but cant copy them.  Just lovely way to end a friday.  Im sure those 48mp images are really nice.  If I log a help ticket I'm sure they will ask me to upload them the files.....