When I updated the plugin "Support System" it failed

Hi.

When I updated the plugin "Support System" it failed and I got theise messages:

Warning: Creating default object from empty value in /home/albertes/public_html/wp-content/plugins/et-shortcodes/et-shortcodes.php on line 135

Fatal error: Call-time pass-by-reference has been removed in /home/albertes/public_html/wp-content/plugins/incsub-support/incsub-support.php on line 447

I'm a beginner in this so don't undestand it.

Best, Tim