I've just taken a look at your site.
User ID 1 on your site is ungovernable.
User ID 64 on your site is charlotte (and looks like they could be a standard user rather than staff/admin).
Based on your screenshot in your first post you're logged in as Libertaire.net which is user ID 3.
So, taking that all at face value, you're not actually logged in as a Super Administrator when you're getting that error.