No matter how you like to participate in developer communities, Pulumi wants to meet you there. If you want to meet other Pulumi users to share use-cases and best practices, contribute code or documentation, see us at an event, or just tell a story about something cool you did with Pulumi, you are part of our community.

Pulumi Community

maybe the attribute `core` was added to the later and it needs updated version of packages. Something similar worked for me.

Try updating if outdate
`npm list`

if list shows outdated package for pulumi, then do
`npm update @pulumi/rancher`

This solved my issue when I was trying to use `initialPassword` attribute for rancher2 `bootstrap` module.

<@UCWG26BH7> helped me this.