Theme does not display settings

[matiasiglesias]

1. Theme Newsprk Child is activated
2. Click on UI Core --> General Settings
3. Message Please activate the theme to gain access to all functionalities and features, and make sure the theme name hasn’t been changed (use Admin Customizer instead) is displayed (despite theme is already activated
4. No theme option is displayed
5. this errors al displayed on developer console Error while parsing the 'sandbox' attribute: 'allow-orientation-lock', 'allow-presentation' are invalid sandbox flags. TypeError: null is not an object (evaluating 'googleFonts['items']') — scripts.js:26