Title: Fatal error when using PHP 8
Last modified: October 7, 2021

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# Fatal error when using PHP 8

 *  [mickwall](https://wordpress.org/support/users/mickwall/)
 * (@mickwall)
 * [4 years, 6 months ago](https://wordpress.org/support/topic/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.
 * The page I need help with: _[[log in](https://login.wordpress.org/?redirect_to=https%3A%2F%2Fwordpress.org%2Fsupport%2Ftopic%2Ffatal-error-when-using-php-8%2F%3Foutput_format%3Dmd&locale=en_US)
   to see the link]_

Viewing 4 replies - 1 through 4 (of 4 total)

 *  Plugin Author [Joe Dolson](https://wordpress.org/support/users/joedolson/)
 * (@joedolson)
 * [4 years, 5 months ago](https://wordpress.org/support/topic/fatal-error-when-using-php-8/#post-14974111)
 * Wish I’d noticed this before releasing this version. Looks like I need to check
   the types of a couple variables.
 *  Plugin Author [Joe Dolson](https://wordpress.org/support/users/joedolson/)
 * (@joedolson)
 * [4 years, 5 months ago](https://wordpress.org/support/topic/fatal-error-when-using-php-8/#post-14974120)
 * I’ll wait on the release; I’ll probably find something else to ship with this
   in the next few days…
 *  Thread Starter [mickwall](https://wordpress.org/support/users/mickwall/)
 * (@mickwall)
 * [4 years, 5 months ago](https://wordpress.org/support/topic/fatal-error-when-using-php-8/#post-15031763)
 * Hi Joe
 * Do you reckon I am good to try php 8 again?
 * Cheers
 *  Plugin Author [Joe Dolson](https://wordpress.org/support/users/joedolson/)
 * (@joedolson)
 * [4 years, 5 months ago](https://wordpress.org/support/topic/fatal-error-when-using-php-8/#post-15033094)
 * Should be, yes. I’ve been running it on PHP8 in dev for the last 3 weeks. Doesn’t
   mean that there’s no possibility of issues, but should be OK.

Viewing 4 replies - 1 through 4 (of 4 total)

The topic ‘Fatal error when using PHP 8’ is closed to new replies.

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## Tags

 * [php 8](https://wordpress.org/support/topic-tag/php-8/)

 * 4 replies
 * 2 participants
 * Last reply from: [Joe Dolson](https://wordpress.org/support/users/joedolson/)
 * Last activity: [4 years, 5 months ago](https://wordpress.org/support/topic/fatal-error-when-using-php-8/#post-15033094)
 * Status: not resolved