Unable To Download. Error Getting License. License Server Communication Problem: E_ACT_NOT_READY

My solution on a MacBook Pro with El Capitan

1. Opened my hidden Library folder

   a. Opened Finder

   b. Pushed & Held “Option” key and clicked “Go” in the title bar (“Library” appeared)

   c. Clicked “Library” while Holding “Option” key

2. Went to /Application Support/Adobe/Digital Editions

3. Deleted the “activation.dat file”

4. Deleted Adobe Digital Editions (I did it with Clean My Mac 3 but you probably won’t need to use it for the deletion)

5. Emptied Trash

6. Reinstalled Adobe Digital Editions 4.5

7. Adobe Digital Editions opened authorization popup, which I filled out

8. My files now open perfectly

I'm having the same problem. Just installed Adobe Digital Editions 4 on my Windows 8.1 computer and can't get to ADE's to download or return books to my library. The Overdrive app seems to be working fine but ADE's won't start? I don't get the open pop up. Books I have checked out of the library show in ADE's when I go to it independently. Sure hope someone has an answer.