They just kept saying 'resource is in use.' But finally I played with the USB computer connection setting on the phone (sorry I don't know how to find it on my phone settings, but it came up under my phone notifications window) so I clicked the 'Camera (PTP)' setting and then went back to the 'Media device (MTP)' checkbox and re-checked it so that I basically reset the software connection on my computer.
Photos work fine and some of my smaller videos were working, but my large videos would not transfer.
I have had the exact same error message showing up on my Samsung Galaxy s4 when I tried to transfer my videos.
