Not able to access settings of Really Simple

The last update included a dedicated capability for the SSL settings page. It will be added to the administrator role.

Can you try adding the following to your theme’s functions.php?

update_option( 'rsssl_current_version','5.3.2' );

Then load your site in the back-end once.

This should run the upgrade again, adding the new ‘manage_security’ capability to your administrator role.

As alternative, I have created a branch which retries the creation of the capability if it wasn’t completed before somehow

https://github.com/Really-Simple-Plugins/really-simple-ssl/tree/check-on-admin-for-completeness-of-capability-upgrade

I’m interested if that resolves your issue, as I havent’ been able to reproduce any issues with this yet.

The above fallback for this edge case situation has been confirmed by another user as fixing the issue.