As part of an acquisitions team, I often face the challenge of transitioning legacy applications to my company’s environment. A common problem encountered is when new users connecting to a new RemoteApp for the first time get stuck with an endless “Initializing connection” message.
After digging deeper, the issue was traced back to the Remote Desktop Protocol‘s recent upgrade to include UDP support for sending session data. Unlike TCP, which is stateful and sends acknowledgment of received data, UDP is stateless and doesn’t send any confirmations.
A simple solution was found by disabling UDP support in the Group Policy Editor (gpedit.msc). This forced RemoteApp to use only TCP, resulting in a slower but stable connection. To do this, follow these steps:
Open the Group Policy Editor by searching for ‘gpedit.msc’ in the Start menu.

Navigate to Local Computer Policy > Computer Configuration > Administrative Templates > Windows Components > Remote Desktop Services > Remote Desktop Connection Client.
Edit the “Turn Off UDP On Client” setting and set it to “Enabled.”

Attempt to reconnect to the RemoteApp and it should work seamlessly.
In conclusion, for slow RemoteApp connections, disabling UDP support in the Remote Desktop Protocol can lead to a more reliable connection by forcing it to use TCP.