DRAFT KB-XXXX Configuring the Connected System Object for OAuth 2.0 integration fails with "The client MUST NOT use more than one authentication method in each request." pink box error

Symptoms

When configuring the Connected System Object using OAuth 2.0, pressing Authorize returns the following pink box error:

Cause

In the Appian OAuth 2.0 implementation, Appian is using basic authentication but also sending the client_id and client_secret credentials in post data of request against token endpoint, as well as in the authorization header. This causes authentication against certain systems to fail with the above error.

This issue has been addressed via AN-104714 in the release of Appian 18.3.

Action

Upgrade to the latest version of Appian.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: October 2018