I have connected my new LG K8 phone to my laptop by USB cable, and the phone appears on windows explorer as a folder 'LG K8 4G' but it says the folder is empty. I know there are music and other files already stored on my SD card in my phone so why aren't they visible? I tried moving a file into the folder anyway and it says 'cannot copy item, the device has stopped responding or been disconnected'. I could take the SD card out and transfer files that way using a card reader but it's a lot of effort to open up my phone each time and it should work via USB cable obviously. Can anyone help?