Error when WinSCP file copy to USB

Sorry in advance if this has been previously answered.

Receive:

Permission denied.
Error code: 3
Error message from server: Permission denied

When trying to transfer audio files using WinSCP to the USB drive in /media/.

Sorry, but this is too vague question.
Do you have any reason to expect to be able to write the files there?
Can you copy the files there using any other method or using any other client?