Has Android 6 Update Caused PC Connection Issues for Galaxy Note 4? Since updating my Samsung Galaxy Note 4 to version 6 of the Marshmallow operating system, it won't show up when I connect it to my PC.  Any recommendations? Is anyone else having a problem?  It may NOT be related to the Android update -- but I've never had this issue before.  Thanks for any help.
Have you changed the USB settings on the phone from just charging to mtp?

Pull down the notification bar while it is plugged in and select the USB notification followed by Mtp which is just file transfer.  

Some info on that:
http://m.androidcentral.com/inside-marshmallow-usb-connection-options