Can I get some help with a problem I am having with a data transfer for the first time?

[AC Question]

problems with data transferring for the first time

Hi:
I usually connect nexus 5 to my laptop, and works fine. I have done it a thousand times.
Now, it does not work anymore. The icon of Nexus appears at the explorer, but nothing inside.
I have tried to connect it to my mac. I have downloaded the application for transferring the files, but then there is a message: "if your screen is locked, unlock it and try again". My screen is not locked, but again the message.

What is going on?

 

[B. Diddy]

Re: problems with data transferring for the first time

Welcome to Android Central! If you recently updated to Marshmallow, be aware that the default USB connection is for Charge Only now. When you connect, swipe down the notification panel, tap the USB icon, and select MTP. You should be able to explore the device on Windows Explorer now.