How to Fix the Error: "Ddedll.dll File Missing or Out of Date"

Background:

TWS users running add-on applications in Excel using DDE on a Windows 64-bit operating systems may receive the following error message upon log in or when enabling the DDE client:

This message is usually displayed for the following reasons:

Other Items:

Please be aware that there are some programs that can effect the legacy DDE Client connections, for example: Chrome, VLC Player, Adobe Creative Cloud or Microsoft One Drive. In case you are using these programs, please keep them closed while you are using the Excel DDE workbook.

The newer DDE version uses a Java socket based on 64-bit, and should no longer have any conflicting software.