I’ve installed ADE 4.5.3 on my Windows 10 laptop and can download and read some of the books in the “Adobe Sample eBook Library” but most only provide a URL to download and I can’t see how to access those.
Examples: “Alice’s Adventures in Wonderland” is downloaded fine (a 1MB acsm file) and I can read it using ADE, but when I click to download “The Adventures of Sherlock Holmes” I just get a URL (1KB acsm file), which I can't seem to add to my Library or open in any way.
I think I figured it out. Having downloaded the URL, and then opened ADE, I click on File=>Add to Library, and then find the acsm file and open it (changing the file type from E-Books to Adobe Content Server Message). It then appears in the Library and can be read.