We apologize for the inconvenience caused, as per the description above, you are getting error "Acrobat failed to connect to DDE server", Is that correct?
Assuming you are using a Windows machine, Please try the troubleshooting steps provided below:
1) Make sure that the application is not open to the Task Manager.
- Go to the Task Manager by pressing Ctrl+Alt+Del.
- Go to the processes in Task Manager.
- End all processes related to Acrobat.
- Restart the computer.
- Launch Acrobat again.
2) Repair the application. Open Acrobat and navigate to Help menu > Repair installation.
3) Check the file association on your system.
If the issue persists, please share the following details:
- Is it Acrobat or Reader installed, check from Help>About Adobe Acrobat.
- Is it a Mac or Windows machine?
- Dot version of Acrobat or Reader installed, check from Help>About Adobe Acrobat.
Hope this helps, and let us know how it goes.
Adobe Acrobat and Reader official update containing the fix for this issue is now available. This update will be automatically pushed to all existing installations of Acrobat and Reader. If you want, you may also manually trigger the update by opening the application and going to Help > Check for Updates.
More information about this release is here: Acrobat Help | Release notes | Acrobat DC and Acrobat Reader DC | Update
Please try it out and let us know your feedback.
Thanks for your patience and support!