diff --git a/main/document/add_link.php b/main/document/add_link.php
index b70b18f81f..5bd4413d06 100644
--- a/main/document/add_link.php
+++ b/main/document/add_link.php
@@ -1,5 +1,6 @@
 <?php
 /* For licensing terms, see /license.txt */
+
 /**
  * This script allows to add cloud file links to the document structure
  * @package chamilo.document
@@ -7,23 +8,24 @@
 
 require_once __DIR__.'/../inc/global.inc.php';
 
-api_protect_course_script();
-
 $fileLinkEnabled = api_get_configuration_value('enable_add_file_link');
-
 if (!$fileLinkEnabled) {
     api_not_allowed(true);
 }
 
+api_protect_course_script();
+
 $courseInfo = api_get_course_info();
 
 if (empty($courseInfo)) {
     api_not_allowed(true);
 }
+
+$documentId = isset($_REQUEST['id']) ? (int) $_REQUEST['id'] : 0;
 $dir = '/';
-$document_data = DocumentManager::get_document_data_by_id($_REQUEST['id'], api_get_course_id(), true);
+$document_data = DocumentManager::get_document_data_by_id($documentId, api_get_course_id(), true);
 if (empty($document_data)) {
-    $document_id = $parent_id =  0;
+    $document_id = $parent_id = 0;
     $path = '/';
 } else {
     if ($document_data['filetype'] == 'folder') {
@@ -35,7 +37,6 @@ if (empty($document_data)) {
 }
 
 $is_certificate_mode = DocumentManager::is_certificate_mode($dir);
-
 if ($is_certificate_mode) {
     api_not_allowed(true);
 }
@@ -47,7 +48,7 @@ if (api_get_group_id()) {
     // If the group id is set, check if the user has the right to be here
     // Get group info
     $group_properties = GroupManager::get_group_properties(api_get_group_id());
-    if ($is_allowed_to_edit || GroupManager::is_user_in_group($_user['user_id'], api_get_group_id())) {
+    if ($is_allowed_to_edit || GroupManager::is_user_in_group(api_get_user_id(), $group_properties)) {
         // Only courseadmin or group members allowed
         $groupIid = $group_properties['iid'];
         $interbreadcrumb[] = [
@@ -174,15 +175,15 @@ echo DocumentManager::build_directory_selector(
 );
 
 // Add tooltip and correctly parse its inner HTML
-echo '<script>
-$(document).ready(function() {
-    $("[data-toggle=\'tooltip\']").tooltip({
-        content: 
-            function() {
-                return $(this).attr("title");
-            }
-    });
-});
+echo '<script>
+$(document).ready(function() {
+    $("[data-toggle=\'tooltip\']").tooltip({
+        content: 
+            function() {
+                return $(this).attr("title");
+            }
+    });
+});
 </script>';
 
 echo $form->returnForm();
diff --git a/main/document/create_document.php b/main/document/create_document.php
index 325e70cbb9..d1ee328e87 100755
--- a/main/document/create_document.php
+++ b/main/document/create_document.php
@@ -67,7 +67,7 @@ if ($is_certificate_mode) {
     $nameTools = get_lang('CreateDocument');
 }
 
-/*	Constants and variables */
+/* Constants and variables */
 $doc_table = Database::get_course_table(TABLE_DOCUMENT);
 $course_id = api_get_course_int_id();
 $courseCode = api_get_course_id();
@@ -116,8 +116,6 @@ if (empty($document_data)) {
     $dir = $document_data['path'];
 }
 
-/*	MAIN CODE */
-
 // Please, do not modify this dirname formatting
 if (strstr($dir, '..')) {
     $dir = '/';
diff --git a/main/inc/lib/usergroup.lib.php b/main/inc/lib/usergroup.lib.php
index d883ca8f03..de2f6c77c2 100755
--- a/main/inc/lib/usergroup.lib.php
+++ b/main/inc/lib/usergroup.lib.php
@@ -206,7 +206,7 @@ class UserGroup extends Model
     /**
      * Gets a list of course ids by user group
      * @param int $id user group id
-     * @param array $loadCourseData
+     * @param bool $loadCourseData
      *
      * @return  array
      */