error message for students, re #9569

lib/admissionrules/coursememberadmission/CourseMemberAdmission.class.php

@@ -124,7 +124,11 @@ class CourseMemberAdmission extends AdmissionRule
                     $errors[] = $this->getMessage(Course::find($course_id));
                 }
             }
+            if (count($errors) < count(json_decode($this->courses_to_add))) {
+                $errors = [];
+            }
         }
+
         return $errors;
     }