Dear Balazs,
this theme is ready for creating child themes. Please see the official guide in the WordPress Codex for more information about child themes.
If your problems continue, please try to deactivate all your installed plugins (one after another), because there might be a plugin conflict which causes this issue. Also verify that your user account has full permissions, because the “Cheatin, uh?” message usually appears when you try to access some content for which you do not have the appropriate access rights.
Best regards,
Tomas Toman
Thanks for the quick response, Tomas.
I used this plugin to create the child theme:
https://wordpress.org/plugins/child-theme-configurator/
It worked before with a different theme so I didn’t assume that there would be a problem with this plugin.
I’ve deactivated all other plugins and couldn’t find which causes the issue.
I own the site and I’m super admin so I guess I have full permission as well.
Any other idea?
Installed a different child theme plugin and that works so I guess the plugin I used caused the problem. thanks for your help.