Custom node can prevent all default nodes appearing in admin view

Bug description

In some cases custom authentication nodes can cause a problem which stops all "out-of-the-box" authentication nodes appearing in the admin console.

How to reproduce the issue

1. an example node which triggers this is on ForgeRock marketplace here: https://github.com/ForgeRock/haveibeenpwned-auth-tree-node
2. build the node and deploy to a AM 6.5 instance
3. login to admin console, choose any tree and notice all standard nodes are missing from the chooser palette

Work around

For this particular node it seems the problem is caused by missing "public" statement on the Config object definition:

change:

interface Config {}

to:

public interface Config {}

then recompile, deploy to fresh AM and all's well.

The same custom node appears to work fine with AM 5.5 and 6.0 however.

Code analysis

OPTIONAL - If you already investigated the code, please share your finding here (remove this text)