Many of us have upgraded their Acrobat Reader to the latest version (Adobe Acrobat Reader DC - ver. 2017). When we try to press on PDFTeXify button to generate a pdf file from the tex file, the current pdf file opened in the Adobe Acrobar Reader DC is not automatically closed and replaced with the new one. Instead, we will get an error pop-up window with a message "Cannot open DDE link to:". 

This problem happens with some \(\LaTeX\) editors, including the WinEdt 8. The reason behind that is because the Adobe company frequently change the process of their dynamic data exhange (DDE), which is the method of interprocess communication under Microsoft Windows. So, the information exhange of the new PDF reader with Windows registry becomes undefined. 

To solve this problem, we have different approaches:

1. Replacing Adobe Acrobat Reader DC with other software.
2. Installing new WinEdt version from its official website on [http://www.winedt.com/]. 
3. Updating the Adobe.edt file.

The first two approaches are strightforward, so we will discuss about the last approach. To do that, please follow the following steps:

Go to WinEdt's configuration folder. If you are using Windows 10, then it is located in the following path:

C:\Users\User-PC\AppData\Roaming\WinEdt Team\WinEdt 8\Config

Replace the Adobe.edt file (it is an ASCII file) located in that folder with the one provided below (it is taken from WinEdt 10, and it is tested with WinEdt 8):

http://www.al-roomi.org/LaTeX_World/Database/Adobe.edt

That is! Enjoy!!