I wrote this on the main news thread, but I’m so late it’s buried and I did enough extensive testing that I figured it was worth a post here. The Files app is still a disaster for external drives. It has a LONG way to go to be ready in time for launch. I would not be surprised at all if external drive support isn’t punted to iOS 13.1 or iOS 13.2. I tried moving 125 RAWs from my a7R III off a 64GB UHS-II Sony SD card onto my 2TB Samsung T5 SSD and it would copy a few and have a “input/output error.” I’m using the new iPad Pro USB-C hub from Hyper. What’s weird is Beta 2 seemed to work better than both Beta 3, 4 and 5. I need to be able to copy thousands of files at once for this to be useful for my workflow of being able to dump SD cards in the field. I tried copying a folder of maybe 25 RAWs from the T5 to the SD card and also had problems and maybe 10-15 copied. So I tried my portable 2TB G-Drive and it also had similar issues. When trying to copy a different folder of about 25 RAWs to the SD card, the iPad just went black in the middle of it and resprung. When it did that the HDD made a bad noise abruptly. When it came back up, the drive was fine and I can browse it no problem, but the iPad completely refuses to acknowledge my SD card now. Weird. When I put the SD card back into my a7R III, it had to completely rebuild the image database like it usually does when I put a wiped card into it. Wow. I haven’t plugged it into my Mac yet to see what the hell happened, but absolutely don’t plug anything into the iPad that you don’t expect to lose. Fortunately for me these were just test shots that I snapped by holding my finger down on the shutter before trying this. I also have copies of both my drives in my studio, and they are also copies of each other. After trying the card in the camera and taking a photo, I tried plugging it back into the iPad. It never recognized it again, even after I left it for a long time. I even plugged it into the Apple SD card adapter, which is different from the one in my hub and fully supports UHS-II at the fast transfer rate, and it didn’t show up with that either. I then plugged in my 128GB UHS-I SD card from Sandisk that I usually use for video. It was immediately recognized, both in the Apple SD to USB-C adapter, and in the Hyper hub. So I tried to copy over 20 a7R III RAW files from my G-Drive to the SD card while in the Apple SD adapter. It had an “input/output error” on the 18th photo of the 20. I then tried to copy that folder back to the G-Drive and immediately got an “input/output error.” I then selected all 18 individually and dragged them over to the G-Drive, and got an “input/output error” on the 16th photo of the 18. I then tried to copy that folder of back to the SD card and immediately got the “input/output error” but it did copy over 3 of the RAWs. I deleted those and manually drug over the 16 photos again, and this time it had an “input/output” error on the 15th photo. So it seems like it just doesn’t want to do the whole batch, even when you copy a batch that worked last time and was even smaller than before. Weirdly, I could quickly copy 35 RAWs in a test from my G-Drive to my iPad, but then copy those 35 RAWs from my iPad to my SD card and it had an “input/output error” on the 29th file. Hopefully they are able to fix this because it takes a lot of extra time to copy things to the iPad in the middle and then over, and then wipe the files off the iPad so you can do another batch, and even then morning everything goes to the SD card on the first try. Fortunately I have nearly a 64GB SD card worth of free space on my 256GB iPad Pro, but it seems like having a bigger iPad Pro will be useful if they can’t figure this out, and it’s still going to be really tedious, which I thought was what they were trying to get away from with iPadOS? What a cluster, and we’re only around 45-50 days from iPadOS launching, and you still can’t even do basic things like copying files between drives. Wow. I’m getting nervous about this feature. Also, after my initial posting this in the news thread, I did some further testing without the hub just transferring files between the iPad and my drives using USB-C and it still had problems, so I don’t think it’s the hub.