diff --git a/main/group/import.php b/main/group/import.php
index 49e98eecef..58acf834de 100755
--- a/main/group/import.php
+++ b/main/group/import.php
@@ -15,8 +15,6 @@ if (!api_is_allowed_to_edit(false, true)) {
 $nameTools = get_lang('Import');
 $interbreadcrumb[] = array('url' => 'group.php', 'name' => get_lang('Groups'));
 
-Display::display_header($nameTools, 'Group');
-
 $form = new FormValidator('import', 'post', api_get_self().'?'.api_get_cidreq());
 $form->addElement('header', get_lang('ImportGroups'));
 $form->addElement('file', 'file', get_lang('ImportCSVFileLocation'));
@@ -74,11 +72,18 @@ if ($form->validate()) {
                 }
             }
 
-            echo $html;
+            Display::addFlash(
+                Display::return_message($html, 'information', false)
+            );
+
+            header('Location: '.api_get_path(WEB_CODE_PATH).'group/group.php?'.api_get_cidreq());
+            exit;
         }
     }
 }
 
+Display::display_header($nameTools, 'Group');
+
 $form->display();
 
 Display::display_footer();
diff --git a/main/inc/lib/groupmanager.lib.php b/main/inc/lib/groupmanager.lib.php
index 4e1446f679..bf615b7e9c 100755
--- a/main/inc/lib/groupmanager.lib.php
+++ b/main/inc/lib/groupmanager.lib.php
@@ -2351,6 +2351,8 @@ class GroupManager
             'groups' => array()
         );
 
+        $courseCode = api_get_course_id();
+        $sessionId = api_get_session_id();
         $groupCategories = self::get_categories();
 
         if (empty($groupCategories)) {
@@ -2485,6 +2487,29 @@ class GroupManager
                     $studentUserIdList = array();
                     foreach ($students as $student) {
                         $userInfo = api_get_user_info_from_username($student);
+
+                        if (!$userInfo) {
+                            continue;
+                        }
+
+                        if (
+                            !CourseManager::is_user_subscribed_in_course(
+                                $userInfo['user_id'],
+                                $courseCode,
+                                !empty($sessionId),
+                                $sessionId
+                            )
+                        ) {
+                            Display::addFlash(
+                                Display::return_message(
+                                    sprintf(get_lang('StudentXIsNotSubscribedToCourse'), $userInfo['complete_name']),
+                                    'warning'
+                                )
+                            );
+
+                            continue;
+                        }
+
                         $studentUserIdList[] = $userInfo['user_id'];
                     }
                     self::subscribe_users($studentUserIdList, $groupInfo);