Accessories not supported by this device

I just updated my iPad Pro 12.9" to checkout the new Files app. However, when I plug in my Lightning compatible external drive (a sandisk flash drive like in Apple keynote), I get a popup error "this accessory is not supported by this device". Is anyone having the same issue?

Replies

I have had mixed results. Im going to do some experimenting with formating drives in differnt manners. Oddly the device that worked best was a pioneer dac that runs on android. I was able to access the sd cards and copy files. Other drives were accesed via the camera kit and required the lightning adapter to be pluged in.

Are you plugging the sd card in via the Lightning or USB-C connector? Thanks!

I doesn't work for me either. NO USB flash drives work. It says it requires too much power. I tried every single flash drive I have - no go. I am using the lightning to USB adapter. It's useless without external power I guess. Really sad since any cheapo Android phone will mount these drives no problems. I am using a $1000 iPad Pro and it cannot mount the USB drives. Oh well....