Tom,
I think I recall having that error as well at some point.
Check line 30 of /enrol/imsenterprise/settings.php where the "require_once" is executed.
Mine is: require_once($CFG->dirroot.'/enrol/imsenterprise/locallib.php');
I think I had to modify it because it would not locate the correct locallib.php in its original form.
Happy new year,
Nikolas