[UPDATE September 11, 2021 - New Link for the application] To fix the message issue " Fatal Error: Acrobat failed to connect to a DDE server" in Adobe Reader by Downloading Adobe Reader DC and Acrobat DC Cleaner Tool for both Operating System ( Windows, macOS) can be download the file ( Feb 9, 2021: 64-bit installer, all tracks ) from https://www.adobe.com/devnet-docs/acr... after download it runs it, then again downloads Adobe Reader from https://get.adobe.com/reader