"Can't Access Device Storage"

[AC Question]

I am attempting to add music to my phone from my computer's music library. When I plug in my Android Nexus 5, I keep getting a message popping up on my computer that says:
"Can't access device storage: if your devices screen is locked, disconnect the USB cable, unlock your screen, and then reconnect the USB cable."
I have tried this answer without success many times. How do I access and update my music collection from my laptop?? (I have a 2008 Apple MacBook Pro).
Is there another way to update my music via internet, or any other method that does not require direct connection?
Cheers

 

[anon(632115)]

How about wirelessly or Bluetooth? You will need a file manage on the phone Xplore is pretty good and just send to your laptop over the network

 

[AlphaTango414]

Make sure you have the latest drivers installed on your computer.