I am having this problem same problem that cucnj described throughout the thread with MZ-NE410 on Windows 10 64-bits
tried many times with different encoding formats (VBR, CBR, WAV) and had no success at all, fail all tracks.
I will try to change the USB cable in question and batteries, but I doubt it will change anything.
btw, I notice SonicStage converts everything before transfer. What format does it convert tracks to?
Maybe having my files converted to the correct format before transfer could fix the issue.