When I developed this plugin, last year, there wasn't a restriction that IPS made to the plugin name on 4.1. So this plugin has a long name and the install "abort". I just renamed it and it works fine:

I only removed the ENABLE from its title and works fine now.

Enable Members Features on New Accounts.xml

Mystery solved! Installed and working on my site.

Thank you very much @Adriano Faria!! 

New (and working) plugin: https://invisioncommunity.com/files/file/8669-new-members-defaults/