Can't save theme settings

Theme settings can't be saved on a newly created site. The following errors showing up in debug.log:

PHP Fatal error: Uncaught Error: Cannot use string offset as an array in /var/web/site/public_html/wp-content/themes/Newspaper/includes/wp_booster/wp-admin/panel/panel_core/td_panel_data_source.php:695

PHP Warning: Illegal string offset 'td_011_tp' in /var/web/site/public_html/wp-content/themes/Newspaper/includes/wp_booster/td_options.php on line 48

PHP Warning: Illegal string offset 'td_social_drag_and_drop' in /var/web/site/public_html/wp-content/themes/Newspaper/includes/wp_booster/td_options.php on line 97