ADE non-responsive when uploading/opening specific book

I am unable to open a specific book in ADE. When I attempt to import the file, ADE becomes non-responsive. Yet, when I look in ADE I see the book listed.When clicking onto the book title ADE becomes non-responsive.

None of my other books freeze ADE and I have been able to download other books from the same source + open them.

So far I have uninstalled/reinstalled ADE, unauthorized/reauthorized my computer, deleted and redownloaded the same file.

I noticed that the file extension is being converted to .epub rather than .pdf. in the My Digital Editions folder.