A temporary workaround is changing Line 17 of wp-content/plugins/event-list/admin/includes/upgrade.php
Before:
private $error = false;
After:
public $error = false;
I’m seeing the same error since upgrading to the newest version.
@wmeric thanks, that solved it for me too
I’m also having the same issue after updating to WP 4.0 – this is a critical issue.
