I’m trying to edit default roles on Administration page: system-minimal, system-full-access and helium-theme-minimal. But can’t do it as all checkboxes are disabled. At the same time I can edit my own custom role.
How to edit default roles?
These are predefined design-time roles provided by platform and add-ons, you can not edit them, you can only create your own roles and use them instead of default ones.