Must-use plugin "disable-s2member-redirect.php" error

We’re moving our hosting from Liquid Web to Nexcess (Liquid Web’s more managed environment for WordPress sites).

They test-migrated our site and discovered this one mu-plugin with filename disable-s2member-redirect.php that was causing a fatal PHP error.

The error was:

PHP Fatal error: Uncaught Error: Call to undefined function create_function() in /hosting-path/html/wp-content/mu-plugins/disable-s2member-redirect.php:2
Stack trace:
#0 /hosting-path/html/wp-settings.php(366): include_once()
#1 /hosting-path/html/wp-config.php(134): require_once(’/chroot/home/a5…’)
#2 /hosting-path/html/wp-load.php(50): require_once(’/chroot/home/a5…’)
#3 /hosting-path/html/wp-blog-header.php(13): require_once(’/chroot/home/a5…’)
#4 /hosting-path/html/index.php(17): require(’/chroot/home/a5…’)
#5 {main}
thrown in /hosting-path/html/wp-content/mu-plugins/disable-s2member-redirect.php on line 2

The host removed that plugin and everything works. Do we need it? Is there an updated version that won’t have this issue?

Thanks!