Reinstalled ADE- Now I cannot side load to Nook- help, please.

HI,

I reinstalled ADE 2.0 and it recognizes and has authorized my computer. I have an adobe account and ID. When I try to side load a library book to my NOOK the dialog box states 'no permission to copy the book'. Why do I get his message and how do I sideload. I reinstalled as books disappeared from the l ibrary view. Now the problem is getting the book to the nook.

Any help is gratefully received.

Thanks.