WHMCS Bridge 500 Error after PHP Upgrade

Hi
I’m getting a 500 Internal Server error after I upgraded PHP from 5.4 to 5.5. When I downgrade, the error goes away. What or where do I go to fix this?

Warning: HTTP Error:22/The requested URL returned error: 500 Internal Server Error at http://me.ca/billing/index.php?systpl=five in /home/me/public_html/wp-content/plugins/whmcs-bridge/includes/http.class.php on line 226

https://wordpress.org/plugins/whmcs-bridge/