Use the search feature to view Kepware's repository of more than 500 Knowledge Base articles. Narrow your results or type your query into the search field below.

Alternatively, if you are unable to find a solution, we have an additional resource - our PTC eSupport Portal . If you are prompted to log into the eSupport Portal, you can use your My Kepware credentials. Need a My Kepware account? Create one here .

Search Solution Results By:
View All Solutions

Kepware Knowledge Base: Solution

Unable to Connect with a NetDDE Client

Last Update: 11/7/2018

NetDDE enables communication between DDE applications installed on remote computers. Due to security concerns, NetDDE was disabled starting with Windows Server 2003 and Windows XP SP2. It was later completely removed from Windows Vista and newer operating systems.

When using NetDDE on a supported operating system, ensure that the NetDDE service is started on both the client and server computer. It will also be necessary to allow UDP Port 137 and TCP Ports 135 and 139 through the firewall.