WordPress E_Error

I have received an email from wordpress with the following email:
An error of type E_ERROR was caused in line 5789 of the file /home/synthivo/public_html/wp-content/plugins/tutor/classes/Utils.php. Error message: Uncaught Error: Call to a member function get_cart() on null in /home/synthivo/public_html/wp-content/plugins/tutor/classes/Utils.php:5789
Stack trace:
#0 /home/synthivo/public_html/wp-content/plugins/tutor/includes/tutor-template-functions.php(479): TUTOR\Utils->is_course_added_to_cart(1093)
#1 /home/synthivo/public_html/wp-content/plugins/tutor/templates/loop/footer.php(10): tutor_course_loop_price()
#2 /home/synthivo/public_html/wp-content/plugins/tutor/includes/tutor-template-functions.php(114): include(‘/home/synthivo/…’)
#3 /home/synthivo/public_html/wp-content/plugins/tutor/includes/tutor-template-functions.php(252): tutor_load_template(‘loop.footer’)
#4 /home/synthivo/public_html/wp-includes/class-wp-hook.php(287): tutor_course_loop_footer(”)
#5 /home/synthivo/public_html/wp-includes/class-wp-hook.php(311): WP_Hook->apply_filters(”, Array)
#6 /home/synthivo/public_html/wp-includes/plugin.php(484): WP_Hook->do_action(Array)
#7 /home/synthivo/public_html/wp-content/plugins/tutor/templates/loop/cours

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