diff --git a/main/auth/inscription.php b/main/auth/inscription.php
index cdcc80d901..f06a54e96f 100755
--- a/main/auth/inscription.php
+++ b/main/auth/inscription.php
@@ -607,8 +607,8 @@ if ($form->validate()) {
                         $admin_info['user_id'],
                         $emailsubject,
                         $emailbody,
-                        null,
-                        null,
+                        [],
+                        [],
                         null,
                         null,
                         null,
diff --git a/main/forum/forumfunction.inc.php b/main/forum/forumfunction.inc.php
index c61658ca5a..c93f016f52 100755
--- a/main/forum/forumfunction.inc.php
+++ b/main/forum/forumfunction.inc.php
@@ -3925,7 +3925,7 @@ function send_mail($user_info = array(), $thread_information = array())
     $email_body .= get_lang('ThreadCanBeFoundHere')." : <br /><a href=\"".$thread_link."\">".$thread_link."</a>\n";
 
     if ($user_info['user_id'] <> $user_id) {
-        MessageManager::send_message($user_info['user_id'], $subject, $email_body, null, null, null, null, null, null, $user_id);
+        MessageManager::send_message($user_info['user_id'], $subject, $email_body, [], [], null, null, null, null, $user_id);
     }
 }
 
diff --git a/main/inc/lib/message.lib.php b/main/inc/lib/message.lib.php
index f16236bfd7..3811c31748 100755
--- a/main/inc/lib/message.lib.php
+++ b/main/inc/lib/message.lib.php
@@ -196,8 +196,8 @@ class MessageManager
         $receiver_user_id,
         $subject,
         $content,
-        $file_attachments = array(),
-        $file_comments = array(),
+        array $file_attachments = [],
+        array $file_comments = [],
         $group_id = 0,
         $parent_id = 0,
         $edit_message_id = 0,
@@ -408,8 +408,8 @@ class MessageManager
             $receiver_user_id,
             $subject,
             $message,
-            null,
-            null,
+            [],
+            [],
             null,
             null,
             null,
diff --git a/main/social/group_topics.php b/main/social/group_topics.php
index 9c72023a40..55ad5f4117 100755
--- a/main/social/group_topics.php
+++ b/main/social/group_topics.php
@@ -70,7 +70,7 @@ if (isset($_POST['action'])) {
             $title,
             $content,
             $_FILES,
-            '',
+            [],
             $group_id,
             $parent_id,
             $edit_message_id,
@@ -86,7 +86,7 @@ if (isset($_POST['action'])) {
             $title,
             $content,
             $_FILES,
-            '',
+            [],
             $group_id,
             $parent_id,
             0,
diff --git a/main/survey/survey.lib.php b/main/survey/survey.lib.php
index 5ff5f54599..172b3160e4 100755
--- a/main/survey/survey.lib.php
+++ b/main/survey/survey.lib.php
@@ -3922,8 +3922,8 @@ class SurveyUtil
                 $invitedUser,
                 $invitation_title,
                 $full_invitation_text,
-                null,
-                null,
+                [],
+                [],
                 null,
                 null,
                 null,