The documentation in https://backstage.forgerock.com/docs/am/6.5/saml2-guide/#federate-with-linking-tree indicates that when configuring a SAML2 authentication module, the Linking Authentication Chain can point to either a chain or tree. However only a chain will work.
This has been created following investigation of
OPENAM-16567. Please see the comments on the Jira for details. Essentially, while the documentation indicates that a tree or chain can be used, the help info in the product for the Linking Authentication Chain, the label and code implementation assumes this is a chain only.
Please can the documentation be updated to reflect that only a chain can be used in the above. From 6.5.2 and later the marketplace SAML2 and Write Federation Information nodes can be used in a tree, see https://backstage.forgerock.com/marketplace/api/catalog/entries/AWt2Ry-ktOjgaXWNPSxp. For 7.0.0 and later, these nodes are included in the AM product.