Was having issues with windows 10 also. Had to do the following. Remove authorization and then reauthorize device. It would not let me do that on ADE. Kept saying to check back later. I did what was below and it now will let me download and read books. I am using ADE 4.
This info is for earlier windows but still works.
1. Quit ADE.
2. Choose Start (Search bar for Cortana)> Search for regedit
3. Right click on regedit,
4.In the left pane of the Registry Editor, locate the following registry key: HKEY_CURRENT_USER\Software\Adobe\Adept
5. Select Adept key, right click on it and select "Delete"
6. In the Confirm Key Delete dialog, click OK.
7. Close the Registry Editor.
8. Open Adobe Digital Editions and reauthorize.