I have a Sony PRS-T1 e-reader with Adobe Reader software installed. It is authorized to read DRM content. Using my PC, I download an e-book from library/Freading. The PC version of Digital Editions is able to open the book fine. However, Digital Editions on PC does not recognize the e-reader. As such, I decided to try transferring the epub file (located under Documents/My Digital Editions) to the e-reader manually. However, while I can see the book, attempting to open it generates this error.
I am not sure if this question would be better directed to a Sony forum or not, but I would really appreciate any pointers on the matter. For example, would a compatibility issue between the version of Digital Editions on my PC (4.5) and the presumably significantly older one on the e-reader cause this? Are there any other files aside from the e-pub itself that the device might need to ensure that i have permission to read the book?
I am not really familiar with DRM technology, so I would really appreciate any advice or pointers in the right direction.
Are you still interested in an answer?
I use Ubuntu/Linux 18.04 and a Sony PRS-T2. I can run Adobe Digital Editions in Ubuntu through Wine.
I'm surprised that you write that your PRS-T1 is authorized to read DRM-content. How did you get is authorized? I think you're mistaken because ADE doesn't recognize Sony e-readers. So you can't authorize a Sony e-reader through ADE. You CAN authorize your PRS-T1 through Sony Reader for PC. Sony doesn't produce e-readers anymore and there's no support neither for e-reader-users nor for the Reader-software. But Reader for PC is still available. The only thing is: Reader is not available for Ubuntu/Linux. It works with me through Wine though. Unfortunately and strangely enough Reader via Wine doesn't recognize my Sony PRS-T2 either.
What I did was: I used a Windows computer with Sony's Reader for PC installed. Then I could authorize my PRS-T2 in Reader for PC through my Adobe account. Then I downloaded books (e-pub) with DRM from the library to my computer and from there I could transfer them to my PRS-T2, not directly with ADE (because ADE still doesn't "see" my e-reader) but in the way that you describe (from the folder ../Documents/My Digital Editions). And I can open my library books on my PRS-T2 with the DRM lifted (for three weeks).