Error downloading Epub

Hello,

I'm not able anymore to open my ebooks via ID Adobe. It says that the ebook contains an error, both with a new ebook I bought as with an ebook I borrowed from the library. So I'm wondering if there is a problem with ID Adobe itself. I already reinstalled it but it doesn't help. Is it possible that it has something to do with the fact I installed ID Adobe for the first time on another computer, connecting it with my ereader? The picture of the error communication is hereby attached.

Thank you for your help!