Adobe Digital Editions 4.5 will not open any more

One solution described in the thread:
https://community.adobe.com/t5/digital-editions-discussions/digital-editions-wont-launch-microsoft-surface-windows-10/td-p/11347635

The error is caused by some file corruption, the solution is to uninstall and reinstall to a different directory.
You also have to rename/delete the "My Digital Editions" folder.

You can try uninstalling the software with 10bit uninstaller and make sure to remove any leftovers. Delete the folder in C:\Users\Current User\Documents\My digital editions. Then reinstall into a new directory under a new user profile or the public one- C:\Users\New user\New folder or C:\Users\Public\New folder. I used the public one and the software works again.

Can anybody believe the internet is full of people having the same problem since 2015?  A quick search for any ADE DRM issue returns 800k+ responses.   I'm sooo tired of trying to get this piece of sh..ware to work.   Not mentionning the broken link to to download he seamingly better V3.0.   Grow up a spine Adobe and fix your products.

Had similar issue, all I could do was find a random old link to edition 4.0 and install that. Seems to work so far, touch wood. Follow these instructions: https://helpx.adobe.com/au/digital-editions/kb/cant-install-digital-editions.html

I have had this problem for ages, I read the suggestion of downloading to the "D" drive and I went through this process and saw it gave the option to browse where you wanted to download to, I noticed then that previously it was downloading the file to the cloud, so I selected the "C" drive on my pc insteaed, now it is working.

I struggled with this issue for a while.  Then I spoke to a librarian, who tried ADE on her home computer and found it worked.  I am guessing it doesn't work on my computer because I have a work subscription to Adobe Creative Cloud which somehow must interfere with my copy of ADE.  So I downloaded ADE on to my partner's computer (he doesn't have a subscription to Creative Cloud) and lo and behold! it worked!

This may be why it sometimes works when you run ADE as Administrator!

 I got that also as one of the errors I have experienced over about a week.I finally uninstalled averything and renamed the "My digital Editions" foldersearched the registryand deleted everything ADE, searched the hard drive and deleted any other pieces of the programs, then reinstalled on a usb flash drive. That worked. I had a little trouble finding the "mydigital editions" ile again but did find it and was able to convert the ADEs to Kindle and regular acrobat and save them. It is sad when we are forced to use a free ptrogram and then the very rich and successful owncompany refuses to support the program because it is free, though compulsory. That experience has just decreased the chances of my ever paying for the new programs. I still have a working CS6, Acrobat X and XI, and lots of Corel and other products tht are as good as Adobe.

I have faced similar issue after a windows update, later this steps solved my problem.
Step 1: Delete the "My Digital Editions" folder or rename it to "My Digital Editions.old", delete would be better
Step 2: Go to this location : "C:\Users\<USER>\AppData\Local\Adobe_Systems_Incorporate"

Step 3: Delete the folder "DigitalEditions.exe" something looks like this:"DigitalEditions.exe_Url_qyaa14c3q2kp5ltfvp1pdpdu"
Step 4: Run the Application again with administrator,(hold shift + right click on app)

Problem Solved!
Happy Reading

I was having the same issue. I tried everything nothing worked. What I ended up doing was hovering over the tab and then right clicking on the small preview window that shows up directly above it, and then clicking "maximize window". This opened it right away. I have to do this everytime but it works nonetheless. Hopes this helps someone!

None of these worked for me except this...

1. Find the Adobe folder on your computer (open file location)

2. Delete the entire folder and its contents

3. Go to recycle bin and delete the files from there as well

4. Download & reinstall Adobe