Android Connection/File Transfer

I am trying to transfer files between my Mac Mini (Lion 10.7.5) and a Nextbook 8. I have the Android File Transfer App installed on the Mac and I have no problem connecting a Kindle Fire HD and moving files. However, when I connect the Nextbook, altho the connection is recognized on that tablet, the AFT app on the Mac finds "No Android Device" . I've been directed to the "Task Manager" on the Nextbook, but all I can find is the "Task Killer".