KB-1185 "The WSDL requires authentication. Please provide valid credentials" error thrown when calling an NTLM-authenticated WSDL


When calling an NTLM-authenticated WSDL with the Call Web Service node, users will receive the following:

The WSDL requires authentication. Please provide valid credentials (APNX-1-4045-006)

If performing a network capture, users will see a 401.


The Call Web Service node does not support NTLM v2 authentication. NTLM v2 authentication can be enforced by the server hosting the WSDL or the servers of the endpoints that the WSDL is referring to.


Disable NTLM v2 authentication on whichever servers are involved with the WSDL call. Steps on how to do this are as follows:

  1. In the server click Start and type Local Security Policy.
  2. Expand the Security Settings > Local Policies > Security Options folder from the left navigation menu.
  3. Scroll down until you find the entry for Network security: Minimum session security for NTLM SSP based (including secure RPC) servers.
  4. Right-click on this setting and select Properties.
  5. In the Local Security Setting tab, uncheck the checkbox for Require NTLMv2 session security. Click OK to save changes.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: March 2017