I currently use an M-Audio Uno, and think I have its latest driver installed for Win 10, 64bit (MIDISPORT 6.1.3 x64), but it doesn't work reliably.  If you've got a Win 10 64bit system and are using Sonar/Music Creator 7 to drive a MIDI controller and it's working for you, which MIDI interface product are you using?

Roland A300.

Thanks, though I'm not asking about the MIDI controller but the interface from your PC to it.  What do you connect the two with?
 

I used a Zoom UAC-2 and an Audient ID-14. Both worked under Win 10. I believe that Roland's latest interfaces also have Win 10 drivers.
 

Thanks again.  And can you confirm your Win 10 is 64 bit, and that you're using Roland's 64 bit driver?