Following an upgrade from Win7 64 Pro to Win10 64 Pro, trying to open a DRM protected eBook which I am licensed to results in an error message.
Trying to remove it and add it again results in "Document is licensed for a different user account".
Trying to de-authorize ADE 4.5.1 fails.
Trying to uninstall and reinstall ADE does not solve the problem.
Trying to run ADE in compatibility mode for Windows 7 has the same outcome.
Edit: Some hours later...
Tried to install ADE 4.5.1 on another PC with W10, same issues.
Uninstalled ADE 4.5.1, from my main PC, deleted all related files. Searched the registry for entries of 'digitaleditions' and 'adept' and deleted those.
Reinstalled ADE 4.5.1 in compatibility mode for Windows 7. Authorized the PC.
It still did not 'behave' correctly for a DRM protected e-book (however unprotected content worked fine, as previously). Tried the Windows 10 trouble shooter, but no clear results. Then tried to open the pdf file of this protected e-book, and suddenly it worked! I cannot say that I know for sure what caused it to work. Tried to shut down and restart the PC, and that e-book still works.
While this was 'sort of solved', it raises the question of long term reliability of DRM protected media, and if that is a smart investment at all.