To start off with, I assume that when you say you're trying to drag and drop files to your sd card, you're doing so while the sd card is in the Pono player. If that's the case, it would probably be easier to just remove the sd card from Pono, and connect it to your computer directly. You would then put whatever files you want on it, remove it, and put it back in the Pono player. But to do this, you'll have to get a micro sd to sd adapter, like I mentioned in my last post. Also, if you don't have a regular sd card slot on your computer, you'll also need to get an sd to usb adapter. Both of those pieces are very cheap and you should be able to get them at a place like Best Buy or Walmart.
I have the exact same setup with a tablet that has a micro sd card. Its a pain to transfer files to the sc card while its in the tablet, so I just pull it out and plug it into the computer directly. I know it may sound complicated, but after you do it once, you'll see that its a fairly simple process. Keep in mind, that the sd card is just another disk drive. It works just like a hard drive or a usb drive.
I have the exact same setup with a tablet that has a micro sd card. Its a pain to transfer files to the sc card while its in the tablet, so I just pull it out and plug it into the computer directly. I know it may sound complicated, but after you do it once, you'll see that its a fairly simple process. Keep in mind, that the sd card is just another disk drive. It works just like a hard drive or a usb drive.