The ebook is a PDF downloaded by opening a ".acsm" file in ADE. (The ebook was from Against the Clock's website, by the way.) It can't be opened in Adobe Acrobat DC. Is/Has anyone else having/had this issue? If so, have you found a solution? I've tried uninstalling and reinstalling ADE, as well as re-downloading the ebook using the original ".acsm" file. The ebook appeared correctly before the update.
I have an older install file sitting on my computer, so, for now, I've downgraded to v18.104.22.168148, which doesn't have the problem. However, I'd still like an answer to this question.