Adobe Digital Editions 4.5 not working with Mac OS X Catalina.

I had a problem with Adobe Digital Edition when I loaded Sonoma 14.1. The guidance on the website was to exclude authorization by going to FIDER to find the library. But this screen doesn't appear, because the finder doesn't display everything. The trick is to press option in the finder and the indicated folder will appear

I had problems for a long time with ADE and Catalina and got by with the workaround mentioned here, but on a second computer I recently updated to Monterey and ADE seems to be working perfectly! Yeah!

I'm in same situation. When you resolv this problem, please, inform here.

If you have an Apple Computer with an M1 chip running the latest macOS version, then the following procedure should solve any downloading problems from a public library you may be experiencing. (It is mainly a summary from the suggestions proposed in the 23 replies submitted so far).

1) Change the name of your Digital Editions folder in the Documents folder (eg  shorten to Dig Ed)  This will preserve any existing book titles you want to keep.

2) Open Finder and hold down the Option key while accessing the Go menu. Library will appear in the list of available options (under Home). Click on the following links in order: Library/Application Support/Adobe/Digital Editions

Drag activation.dat and any other files that may be lurking in Digital Editions to Bin. ie Delete them from the computer!

3) Delete all versions of Adobe Digital Editions from your Applications folder.

4) Download Adobe Digital Editions 4.5 from the Adobe website.

5)When you first open the app, click on Help/Authorise Computer. Select Adobe id from the long list of registration options. You must now create a new identity, email address and password for yourself. Anything less will be rejected by the Adobe administration. You must use an email address you have never registered with Adobe before (Your Apple id perhaps?). Change your name! (a slight change in the spellings should do) and invent a completely new password.

Your computer will be authorised almost immediately.

6) Log in to your Public Library acccount and select a book to download that you have not previously downloaded on to any of your Apple devices. This book will now appear on the Library page of ADE 4.5 ready for transfer to your Kobo ereader or whatever.

I can't tell you how frustrating I found this problem! But I'm happy to tell everyone I found a roundabout solution to it. I downloaded the overdrive app onto my phone and signed in with the same information I used for my Kobo. I then synched my Kobo and the books downloaded onto the ereader and I was FINALLY able to open them. I hope this helps! Totally ridiculous that Adobe and Kobo have not solved this issue yet 

The solution for me, my issue being 'loan token not found',  believe it not, was to 'borrow' an 'old book' from overdive/library.

I had previously spent countless  frustrated hours, on just about all the other suggested solutions (including uninstalling ADE, deregistering devices, wiping, deauthorizing, reauthorizing, removing hidden files/dirs, synching accounts, reinstalling, every solution out there - even went so far as completly wiping my nook) all to no avail. I was to the point of 'OK I'll give up on my Nook.  I'll buy a kindle,  I'll just buy paperchecks, I'm done I give in'.

The only thing I did, in beween the  'not working pulling my hair out' and the 'working' phase, was to delete ( not return) the books on my nook ( via ADE) and then borrow an 'old title' from overdrive/library and then load that 'old title'  onto nook via usual method. After that 'old title' opened successfully on nook, I could copy over and open all the more recent titles.

Running Cataline w/ ADE 4.5.11 and an old nook glowlight.  For the 'old title' I just sorted the 'Available Now' titles by 'Date Added' and chose the last page of titles available ( which was 'Crusader Gold' by David Gibbins - which I feel obligated to read now). The thinking behind the solution is that somehow the DRM, or the way it's being applied *by the ibraries/overdrive*, has changed by date - and intially loading an 'old title' seems to reolve the issue ( at least it  did so for me after many.many hours on trying other solutions).  ( Hard to believe I know, YMMMV)

I had the same problems. I now download my epub book via Overdrive to my iPad and then sync my Kobo. The book then loads in my Kobo. Both the iPad and Kobo are on my Wifi network.

I'm also having these same issues, SO frustrating! But at least - after all the hours I've wasted trying to overcome the issue - it's nice to finally know it's an Adobe 4.5 problem (and a Mac Catalina + ADE 3.0 incompatability) - and not just me!! Is there not a way to transfer library-borrowed ePub books to a Kobo without having to utilise ADE as an intermediate?

I've been having the same problem and tried all the same troubleshooting steps that everyone else has. I really miss being able to borrow ebooks in these days when the physical libraries are closed! Does anyone know if Adobe is working on this? Is there a way to ask them to? By the way, as many others have probably discovered during this adventure, Rakuten Kobo's technical assistance is appalling.

Same exact issue: I installed the latest iOS on my mac (macOS 10.15 Catalina) and it wouldn't let me run Adobe Digital Editions 3.0. 

I was using Adobe Digital Editions 3.0 because I was unable to open books downloaded from Overdrive to my Kobo using more recent software.

I have tried re-installing, and deauthorizing the Kobo and the computer. Any other fixes?