“Add Widget” does not appear on the dashboard

[Luis Gustavo R1]

The “Add Widget” (+) button is not appearing on the dashboard. I have the platform admin role and permissions to edit reports and dashboards. I also tried configuring the com.snc.pa.dashboard.editable property and other related properties, but the issue persists. All widgets from sys_widgets are enabled.

Do I need to install any plugin?

Could someone help me identify what might be causing this?

[ShaidaC]

The add new element has limited options and doesn't contain iFrame

[jeffrubinoff]

You cannot add Core UI widgets to a Platform Analytics dashboard. Options that are not in Add new element are not supported.
You can create or edit a Core UI dashboard and add widgets there, provided your relevant properties are set to True: