Adobe Digital Editions 4.5 will not open any more

Hey, I had the same problem and it turned out to be related to screen settings. I'm switching workplaces and connect different external screens with different settings. ADE somehow always opens on the screen it was last used on, even though the screen is not connected. 

Try to move the window with cmd + arrow keys to your screen!

I encountered the same problem and I tried a lot. Because the application showed in the task bar, I had the idea was opened, but on another screen. The thing was that I only had my laptop screen, no second screen. I connected my laptop to another screen with HDMI and the application appeared on the second screen. Hope this helps!

For me i thought maybe it was still registering my monitor even though it was disconnected tried all the usual win+arrow key, changing to pc only, changing to duplicate and moving to new desktop. The preview-window shows when i hover over it on the taskbar but clicking it didnt open rebooting laptop / ADE didnt work either. I just right clicked the preview window and chose 'Maximise'. every few months i forget this happens so i just search for it and keep coming to this thread. So hopefully this helps you and will help future me if if forget again. i am running win11 with ade4.5

I know this is old and has a correct answer already, but I had this same problem. I'm on my work computer and hence I'm locked to version 4.5 and do not have the admin rights to run it, so I had to find another solution. I didn't need to install the older version to get it to work.

Here's my setup: Windows 10 Enterprice, and ADE4.5.11. I had the problem that ADE was launched outside the screen.

I had probably used it on an external monitor the last time and it was not connected now. However, ADE had stored the last location into "user.config" file, which is stored in the location where ADE is installed in my case the folder was named DigitalEditions.exe. I got the window back on screen by opening the config file in text editor and changing the coordinates in the row having the "MainWindowLocation" by removing the first number on the line and rebooting the software. I hope anyone else having this problem sees this and can avoid the frustrating process I had to go through to find the solution.

This is a clear oversight by the developers, and if any of you see this I would hope that you reconfigure the software so that the MainWindowLocation is not stored to the user.config file.

Your windows is not the problem, Adobe is fully aware of the problem with both ADE versions and don't wanna fix it. I'm waiting on the publisher to tell me what other ebook reader i can use so i can get rid of ADE 

coz it's trash and a lame excuse for software 🚮

I got this issue today with the 4.5.11 version. What solved it for me was this:

1) Uninstall the program.

2) Install it again from https://www.adobe.com/solutions/ebook/digital-editions/download.html

3) When the installer asks you where to place the program, change it to a different folder than the default. I selected Programfiles (x86). I'm guessing it would work also in the regular Programfiles folder.

That was it. I ran the program and it worked perfectly.

Had the exact same issue. Just stopped working today. Step 3 "Changing the directory" of the following article fixed the problem for me:
Adobe Digital Editions Not Responding: How to Solve (fixthephoto.com)

Instead of letting the program install in the default "Program Files (x86)" folder, I changed the install location to the "Program Files" folder. Hope this helps other lost souls struggling with this garbage software.

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.

See also:

https://community.adobe.com/t5/digital-editions-discussions/digital-editions-wont-launch-microsoft-surface-windows-10/td-p/11347635

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.