# Desktop Connection Fails with “No stuffable upstream security type found”

- Link: https://www.agilicus.com/faq/desktop-connection-fails-with-no-stuffable-upstream-security-type-found/
- Published: 2025-02-03T20:32:54+00:00
- Author: Kyle Larose

If your VNC desktop has credential stuffing enabled (i.e. it has an entry in one
of the username or password fields in its expanded configuration under Resources/
Desktops), the connector and VNC server must mutually support a protocol which allows
for credential exchange. If the connector cannot negotiate a protocol compatible
with credential stuffing, it will fail with this message. The following screenshot
provides an example. Note the red bar.

![Agilicus Desktop Connection Error: 'No stuffable upstream security type found'.
This error indicates a problem with the security configuration preventing a secure
connection. Refer to the Agilicus FAQ for troubleshooting steps to resolve the connection
failure.](https://www.agilicus.com/www/61551f62-image-1024x220.png)

The connector supports the following protocols which allow for credential stuffing:

 * VNC Authentication (Type 2)
 * RA2 (Type 5)
 * RA2r (Type 13)
 * RA2_256 (Type 129)

To overcome this problem, either disable credential stuffing, or configure the server
so that it supports one of the above protocols.