Hi! I recently purchased a sound pack for my MKI but Transfer doesn´t recognize the sounds folder when I tried to drag it. The message is “files not supported by device”. I don´t have any problem with samples files and both softwares version are updated (Transfer and MKI).
Please help! Thanks in advance 
“Device fail with operation” is the other message I read if I tried to drop the folder from the main page in Transfer. I can´t understand why it happens just with sound files, specially being included in the official Elektron site. I forgot to say that I work with Windows10 and 4GB of ram. I´m getting crazy to find the bug!
Is your firmware up to date?
Yes, everything was ok, I tried again after a couple of days and finally it worked. I still don´t know why it failed in the begining.
I know this is an older thread, but it happened to me today on Digitakt 1.50 (latest firmware). Turns out I had to drag in the sample files, it was throwing this error when I tried to drag in the parent folder.
HTH!
Cheers,
-loops