Fatal error: Uncaught TypeError: Return value of HQRentalsPlugin\HQRentalsHelpers\HQRentalsDatesHelper::convertPhpToJsFlatpickrFormat() must be of the type string, null returned in /home/customer/www/slingshotrentalssouthbeach.com/public_html/wp-content/plugins/hq-rental-software/includes/helpers/HQRentalsDatesHelper.php:140 Stack trace: #0 /home/customer/www/slingshotrentalssouthbeach.com/public_html/wp-content/plugins/hq-rental-software/includes/assets/HQRentalsAssetsHandler.php(581): HQRentalsPlugin\HQRentalsHelpers\HQRentalsDatesHelper->convertPhpToJsFlatpickrFormat('') #1 /home/customer/www/slingshotrentalssouthbeach.com/public_html/wp-includes/class-wp-hook.php(308): HQRentalsPlugin\HQRentalsAssets\HQRentalsAssetsHandler->registerAndEnqueueFrontEndGlobalVariables('') #2 /home/customer/www/slingshotrentalssouthbeach.com/public_html/wp-includes/class-wp-hook.php(332): WP_Hook->apply_filters(NULL, Array) #3 /home/customer/www/slingshotrentalssouthbeach.com/public_html/wp-includes/plugin.php(517): WP_Hook->do_action(Arr in /home/customer/www/slingshotrentalssouthbeach.com/public_html/wp-content/plugins/hq-rental-software/includes/helpers/HQRentalsDatesHelper.php on line 140