error 2038 IO Error on Network Request. Please check your network connection and try again.

I have Windows 7 and solved the issue with an update...

Windows: http://download.adobe.com/pub/adobe/digitaleditions/ADE_2.0_Installer.exe

I have the same problem. The error I get says " "Digital Editions could not connect to the fulfillment server. Please make sure you are connected to the internet." When I contacted what Adobe calls (with an apparent straight face) "Support" I was told that this product is no longer supported. How is that possible?

The newest Kobo update fixed the problem.

Have read through all the different posts on this site and on other sites.

Below is what finally got rid of the Network IO error (for MAC)

Mac users

1. Uninstall ADE and remove it from the trash.
2. Restart your computer.
3. Downloaded  latest ADE from Adobe’s website and install it
4. Authorized my computer in ADE using the HELP menu and selecting “Authorize Computer…”

After you've gone through the above steps, try downloading the title again.

Finally got it working again.

First I returned all borrowed books from before it quit working (funny that I can return books but not download new borrows).

I uninstalled Digital Editions. In addition to the Adept registry (tried that fix but didn't do the trick for me), took these extra steps to make it look like had never had a previous version on my computer.

   1) renamed the My Digital Editions folder in Documents that contains all the books. This way I still have the books saved.

   2) deleted Digital Editions folder found in Program Files (x86)\Adobe

Note that I first tried it without doing step 2 & got same 2038 error. So had to repeat process & added step 2.  Don't think there were any other Digital Editions folders, but if you find them, delete them & all subfolders & files inside.

Then downloaded latest Digital Editions fresh from their website. Have to login with Digital Editions password & register your computer again, since all previous info is gone.

Held my breath when retried first download that failed and was so glad it worked, as book was going to expire in 22 hours & I would have had to go to bottom of hold list to get again. I downloaded all books that previously failed, regardless of which computer I had initially tried. After the first 2 failed, I thought maybe it was that computer & tried another family member's on a third book. So was afraid would have to use same computer as first tried, but since they were unsuccessful, guess there was no link to specific computer.

Hope everyone else can get same success, as this has been almost 2 weeks not working.

So, I was having this problem as stated earlier.  I managed to fix it by deleting my older version of ADE, installing the newest version, going into the registry and deleting the adept key, then reauthorizing ADE.  I was then able to download form overdrive with no issue.  Hope that can help.

I deleted my old version, installed the newest version of ADE, deleted my adept registry, and it still won't let me de-authorize ADE. It keeps telling me to "try again later".

Same issue, borrowed 8 library books but can't download any of them yet it worked fine last week. I think it's an Overdrive problem as I've just tested Digital Editions by downloading a book from their free library and Adobe both opened and downloaded the book perfectly...but how to let Overdrive know the problem is with them?

I've tried this fix too and it doesn't work for me.  Won't let me delete the Adept key from the registry.  I have the free version of Avast and just updated it a few days ago.  Could this be the issue?

I got the latest 4.5 version of ADE working again!  I tried re-installing the old version of ADE that I had (1.7.2) that had stopped working but continued to get the 2038 error.  So I did this on my Windows 7 system:

1.  I uninstalled ALL versions of ADE with Cleanse Unistaller Pro that also deleted all ADE registry entries.

2.  Deleted all cookies on my browser.  I use Chrome.

3.  Re-installed the the latest version of ADE 4.5.2. 

4.  Pressed CTRL-SHIFT-d to de-authorized ane re-authorized ADE with my email address and Adobe ID.  When I tried to download an epub library book, I got an activation error.  I researched the Adobe forum to fix activation errors and found the following:

1.     Close all applications.

2.     Choose Start > Run.

3.     In the Open text box, type regedit and then press Enter. The Registry Editor opens.

4.     In the left pane of the Registry Editor, locate the following registry key: HKEY_CURRENT_USER\Software\Adobe\Adept

5.     Select the Adept key.

6.     Choose File > Export.

7.     In the Export Registry File dialog box, select Selected Branch under Export Range. Enter a name and location for the backup registry key, and then click Save.

8.     Right-click the Adept key and choose Delete.

9.     In the Confirm Key Delete dialog, click OK.

10.     Close the Registry Editor.

11.     Open Adobe Digital Editions and reauthorize.

The above got rid of the activation error.  I am now able to download all epub books 3 libraries of which I am a patron.  I know the fix sounds complex but until Adobe fixes the issue, this worked.  The old version of ADE 1.7.2 stopped working on November 30 , 2016 after working perfectly fine for over 3 years.