Fatal error when running a report

I’m getting the following error when I go to the products report tab.

Fatal error: Uncaught TypeError: Unsupported operand types: float + string in /www/public/wp-content/plugins/sales-report-by-state-city-and-country/includes/class-devsoul-psbs-general-functions.php:187 Stack trace: #0 /www/public/wp-content/plugins/sales-report-by-state-city-and-country/includes/admin/views/product-sales-report.php(378): devsoul_psbs_get_product_sales(124863, Array) #1 /www/public/wp-content/plugins/sales-report-by-state-city-and-country/includes/admin/class-devsoul-psbs-admin.php(177): include(‘/www/public…’) #2 /www/public/wp-includes/class-wp-hook.php(310): Devsoul_Psbs_Admin->devsoul_psbs_tab_callback(”) #3 /www/public/wp-includes/class-wp-hook.php(334): WP_Hook->apply_filters(”, Array) #4 /www/public/wp-includes/plugin.php(517): WP_Hook->do_action(Array) #5 /www/public/wp-admin/admin.php(259): do_action(‘woocommerce_pag…’) #6 {main} thrown in /www/public/wp-content/plugins/sales-report-by-state-city-and-country/includes/class-devsoul-psbs-general-functions.php on line 187