I have the same problem. Opening a pdf inside a browser doesn't work. Opening a pdf either in Acrobat Reader X or Acrobat 9 Pro. Sometimes a pdf opens after more than 5 min! But even than Acrobat freezes, the top showing "File", "Edit" etc. disapears!  I uninstalled any security programs with firewalls; no changes. Uninstalling and reinstalling doesnt work. Making pdf's with any software is no problem. I use Windows XP running Adobe CS4. Any help?

I started to get  the same problem today.

I tried the <shift> "open with..." Doesn't work.

I think Adobe should provide an answer immediately. Most of my files are in Acrobat!!

Adobe Reader function returned after rebooting - but it came up slowly. Now I'm worried. I've been using Windows 7 for a year with Spyware Doctor without problems. I haven't done anything to the machine and I haven't installed anything new for months.

Where did this "Acrobat failed to connect to DDE Server" spring from?

I just got an Adobe upgrade and the problem has gone. What the...!

Yup.

Thank you peter. I also updated the terminal servers and will see what happens next week.

The problem disappeared as soon as I loaded the latest (at the time) update.

I don’t use Symantec and Windows Defender was “OFF”.

I have just today begun having the same problem. Adobe Reader X on Win 7 pro 64bit SP1

Can't be Symantec. I use MS Essentials security.

Can't make any changes via Adobe Reader, either, because it won't open -- even when I try to launch directly from the target EXE file.

This is making a LOT of PDFs unreadable and I am not happy.

I am getting a similar error - and I wasnt working with a PDF - I was using Filezilla to transfer files and two identical DDE erros pop up seemingly randomly - I will try and figure out how to replicate the error.

I dont seem to have any problem opening a PDF normally tho - I have Reader X and recently installed 9 Pro.

Take the updates. That should fix the issue.

Yo Carey! ( guess what I gots - An Acrobat 9 Pro ACE )

Well, I have reader X installed.. but that is neat to know. So the troubleshooting path here seems to be..

1. Verify update status of the software.

2. Verify that active security policies are not interfering with the software.
3. Check if the problem happens in another user profile.

Hehe, we have two different scenarios here actually.. in my case the error is simply appearing. I dont have to be using PDFs or have either Reader or Acrobat running - which means the fast laucher / acrotray software is capable of generating the error. In other cases certain PDFs are failing to open, and in others the entire system is not launching..

Here is a thought - since the DDE naming conventions were changed in the Acrobat X would it be possible that the error is arising from having 'nonsanguine' versions of Acrobat and Reader? Say you have acrobat 8 but you recently installed Reader X - the behind the scenes program naming conventions are now different, but the systems are attempting to use the same resources. Perhaps this is the reason the problem is occuring? Obviously some sort of permissions issue is involved.. or changing security policies wouldnt do anything.

@All - is anyone experiencing the error with Acrobat X and Reader X installed?

Something obviously went wrong durring the installation of 9.5 - running an update is certainly not *intended* to stop you from using the product. What the hell happened is there was a permissions or resources issue - or a software conflict on you system when you ran the updarte. That is what the hell happend Ksub

You could speak with Apple care and they would probably be able to get you through the uninstall and reinstall of the software - which is most likely what will have to happen at this point. You should also ask them about basic preventative system maintenance. I assume you were getting the DDE server error and this is what prompted you to run the update?

Intruiging.. its happening on both Mac and Win - well - You *were* getting the DDE error prior to or now that you have installed the update?

Do you have Reader X?

Message was edited by: TheShea

We have been getting the "Fatal Error: Acrobat failed to connect to DDE Server." message for quite some time without any consistent way of making the error happen.

We have six VM Citrix servers running Windows Server 2008 R2 Standard v6.1.7600.1, Microsoft Dynamics SL v7.0 Feature Pack 1 - Professional Version 7.03.40312.01 (7.0.0.0), Adobe Acrobat Standard X v10.1.2.  We use Kaspersky AV 6.0 for Windows Servers for our Endpoint Protection.  Users use Citrix to run Dynamics from their local machine and when creating PDFs with BullZIP PDF, it will open PDFs in Acrobat Standard.

This was happening when we had Acrobat Standard v9 as well.  We tried uninstalling and reinstalling Acrobat to see if that would fix it, but no joy.  We tried upgrading to Adobe Standard X to see if that would fix it, no joy.

Reading on these threads, to turning off Protected Mode,  The instructions say to Disable Protected Mode, you go to Edit > Preferences > General and deselecting Enable Protected Mode at startup.  However, when I get to that window, there in no check box for this.

Any other thoughts?  We're going crazy...