eReader not authorized to open this book

I had this same problem. I followed these instructions on the Overdrive help page at https://help.overdrive.com/en-us/0926.html  for "Content locked" error or book won't open on a Kobo ereader and was finally able to open my library book on my new computer without getting the "This book is protected by DRM message". You have to delete the problem book from your Adobe digital editions and your Kobo. Then deauthorize both your Kobo device and your computer and then reauthorize both. Reauthorize both your computer and your Kobo device and reimport the book from the library. After doing this, I was able to open the book on my Kobo. 

I'm shocked to see that this issue goes back so many years with still no tried and tested fix to the issue from Adobe. I too am having a similar issue. I am able to download books from my library and they work perfectly with ADE, but when I download a book from Indyreads, which is also through my library, those books won't work on my Kobo. I get the same error that everyone else seems to get. I have read back through everyone's posts and have tried so many different things, but still cannot get anything to work. I'm wondering if there is possibly some setting that I may have overlooked? Any help would be greatly appreciated. 

There is a really easy solution to the Adobe Editions problem.  I went out and purchased a Kobo Libra and it connects directly to the library through Overdrive and you no longer have to endure the Adobe Editions problem to download books.  It took me many angonizing hours of trying to fix this annoying problem and in the end I gave up.

HAVING THE SAME PROBLEM THAT LIZM HAS:HELP HELP HELP HELP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

When I download a book from my public library I can open it in digital editions 4.5 but when I transfer it to my device (kobo) and try to open it on the kobo it says "This book is protected by DRM. Because you previously deauthorized your eReader, you need to re-import the book using Adobe Digital Editions." I tried erasing authorization and setting git up again but it still won't work. Erased and downloaded a new edition of ADE, that didn't work either. Tried different books and libraries but still have problem. Called kobo and after troubleshooting with them they say it as ADE problem. Please please please help! Thank you!

So I too am having this issue with my wife's Kobo Touch.  Worked with 4.5 2wks ago then stopped with the new book we got yesterday.  ADE3.0 won't run on my Windows 10 system.  I have tried reauthorizing ADE with my OverDrive login and same results.  Not sure where to go from here.  Any suggestions please!

My problem is exactly as the original poster LizM described back on Nov. 4, 2017. I was however, able to check out a book from our local library through the OverDrive app on my android phone, and it appeared on my Kobo Clara and opened just fine. The problematic books that won't open on my Kobo Clara are the books with DRM I have downloaded from Internet Archive/Open Library. I am print-disabled, and there are many books that  I would like to read that cannot be purchased in the US as an ebook. Sending imploring emails to publishers over the years has been ineffective. Because Open Library has scanned some of these books, I bought a Kobo Clara to be able to read them more comfortably.  Interestingly, I can open the problematic book on my computer and on my phone -- just not on my Kobo Clara. Tonight I will see if my PC will allow me to download ADE 3.0. I have tried just about everything else.

This is still an issue for me. My authorized (and un-authorized and factory reset and re-authorized) Kobo won't let me read a book from my library. Honestly, I would have less of a problem with this DRM nonsense if it actually worked, but locking me out of a book I legitimately check out of the library is absolutely ridiculous.

Adobe, when the solution to a problem winds up being "install an older version of the software," that's a problem that shouldn't take 4+ years to fix.

As a piece of software for library management, Adobe Digital Editions is about as good as a torn shoebox. If your goal is to prevent piracy, you have to make the non-piracy options viable. This is how things work.

It seems my Kobo issue is exactly as described above in 2017, yet in 2021 neither Adobe nor Kobo could advise me to uninstall latest upgraded ADE and use version 3.0. After 3 days trying, in the end a simple resolution (well working so far). Can Adobe not fix this issue in newer versions of ADE?

I had the same problem! But when I tried to take the book out with overdrive it said the book wasn't available in my region (I live in Canada)? So maybe check to see if the file is available in your country because it worked just fine with another book. 🙂

I've spent two hours deauthorizing and reauthorizing both my laptop and my KOBO, still not working. And I'm tech savvy.  ADE has to be the single worst design in the history of digital technology.  It's awful.