Fatal error when using PHP 8

Hi Joe

Ive recently tried to upgrade to PHP 8, I thought everything was fine and then I sold a ticket, Then the paypal IPN came through it cause a failure. Stack trace below

[Thu Oct 07 20:53:47.580088 2021] [proxy_fcgi:error] [pid 3119988:tid 140422512883456] [client 172.69.62.85:33378] AH01071: Got error 'PHP message: PHP Fatal error: Uncaught TypeError: Unsupported operand types: string + string in /var/www/wordpress/wp-content/plugins/my-tickets/mt-cart-handler.php:372\nStack trace:\n#0 /var/www/wordpress/wp-content/plugins/my-tickets/gateways/paypal.php(101): mt_check_payment_amount()\n#1 /var/www/wordpress/wp-includes/class-wp-hook.php(303): mt_paypal_ipn()\n#2 /var/www/wordpress/wp-includes/class-wp-hook.php(327): WP_Hook->apply_filters()\n#3 /var/www/wordpress/wp-includes/plugin.php(470): WP_Hook->do_action()\n#4 /var/www/wordpress/wp-content/plugins/my-tickets/my-tickets.php(592): do_action()\n#5 /var/www/wordpress/wp-includes/class-wp-hook.php(303): mt_receive_ipn()\n#6 /var/www/wordpress/wp-includes/plugin.php(189): WP_Hook->apply_filters()\n#7 /var/www/wordpress/wp-includes/template-loader.php(104): apply_filters()\n#8 /var/www/wordpress/wp-blog-header.php(19): require_once('...')\n#9 /var/www/wordpress/index.php(17): require('...')\n#10 {main}\n thrown in /var/www/wordpress/wp-content/plugins/my-ti...'

I’ve gone back to 7.4 and all is well again.

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