Fatal error / chron issue since version 2.7.5

After updating to the most recent version, 2.7.5, we got a chron error when one of our pieces of content was set to expire. After checking the error log we saw this repeated several times:

[20-Jun-2022 20:50:01 UTC] PHP Fatal error:  Uncaught Error: Call to a member function save() on boolean in /htdocs/wp-content/plugins/post-expirator/post-expirator.php:804
Stack trace:
#0 /htdocs/wp-includes/class-wp-hook.php(307): postexpirator_expire_post(3880)
#1 /htdocs/wp-includes/class-wp-hook.php(331): WP_Hook->apply_filters('', Array)
#2 /htdocs/wp-includes/plugin.php(524): WP_Hook->do_action(Array)
#3 /htdocs/wp-cron.php(138): do_action_ref_array('postExpiratorEx...', Array)
#4 {main}
  thrown in /htdocs/wp-content/plugins/post-expirator/post-expirator.php on line 804

We reverted the plugin and it seems to be working now, but we won’t be able to update until this issue is solved. I don’t know much about what is happening, but was asked to report it to your support.