I just replaced my old B&N Nook with a new Galaxy Tab4 Nook. I download a lot of books from my public library and I use Adobe Digital Editions to do that and then transfer to my reader. My old Adobe Digital Editions did not recognize the new Galaxy Tab so, on the advice of B&N tech support, I uninstalled Adobe Digital Editions 2 and then downloaded the new version (4.0.3). No joy. The new Galaxy Tab still does not show up in Adobe Digital Editions.
I have tried attaching the Galaxy Tab and then launching Adobe and I have tried the reverse. I have also tried switching to another computer USB port. Nothing works.