I upgraded from Windows 8.1 (where ADE was working OK) to Windows 10. ADE worked OK for a couple of days (I successfully downloaded two books from my library & copied them to my ereader). Today ADE only shows the 'Bookshelves' in the left pane, not the expected 'Libraries' etc. I appear to be able to 'fullfill' when I select a downloaded .acsm but the resulting displayed book is not accessible (no response to clicking on it) I have tried uninstalling & reinstalling 4.5 & tried 3.0 with the same results. The help/authorisation says that it is authorised, but I have tried unauthorising & reauthorising with no effect. If I attach my Kobo ereader today it appears under 'devices' as usual but if I select it ADE displays an error pane 'ADE 4.5 has stopped working' with the only option to close the program after the normal 'windows is checking...'. Intermittently the entire ADE screen has no selectable buttons (file, library, help, etc.) including even the close program (top right).
Sort of the same problem here. After upgrading to Windows 8 the whole program doesn't start. I tried to reinstall but it doesn't help.
It is not 'Libraries' that is missing it is the display 'All Items' 'Not Read' etc.
Found solution which works so far on web:
Rename the location where ADE keeps its books (the epubs) -- e.g My Digital Editions -- to something else; Create a new folder with the original name. Restart ADE. You should then be able to download books etc. You may get an 'Activation Error' if you do unauthorise ADE then reauthorise it. You can get books previously downloaded by simply copying them from the renamed folder.
No idea why this works, but....