I would first start off with checking the supervisor capability under Tools and User Management to make sure you are listed. Then I would check the "teams" settings under Subsystem/RmCm and choosing the appropriate team and checking the selections for both the primary supervisor and secondary supervisor selections to see if you are listed.
Are you getting this error “Installer User Interface Mode Not Supported. The installer cannot run in this UI mode. To specify the interface mode, use the -i command-line option, followed by the UI mode identifier. The value UI mode identifiers...
The below trick might come handy when you have to add a new node to a cluster but you don't have or is unsure of the security password for the publisher. This procedure has been around for ages.
1) Login into the CLI of the Publisher.