When upgrading to Windows 10, the error "Unable to Download Error Retrieving License License Server Communication Error: E_ADEPT_DOCUMENT_OPEN_ERROR" may occur with ADE.
The error occurs when the Read / Write permissions for the ../My Digital Editions directory were not set correctly when upgrading to Windows 10. When logging in with the (newly created) Microsoft account instead of a local user account, access is no longer available.
The logged in user must have read and write access to the ../My Digital Editions directory.
Manually restore permissions for the locally logged-in user to the ../My Digital Editions directory.
Uninstall and then reinstall ADE. Use the user you will use in the future.
In the opposite case, if the Microsoft account should also be granted access to the directory, use the email address associated with the Microsoft account as the username.