diff --git a/main/forum/editpost.php b/main/forum/editpost.php
index ec7baa2748..050eb61470 100644
--- a/main/forum/editpost.php
+++ b/main/forum/editpost.php
@@ -131,8 +131,7 @@ if (isset($_GET['origin'])) {
 if ($origin == 'learnpath') {
     include api_get_path(INCLUDE_PATH).'reduced_header.inc.php';
 } else {
-    Display :: display_header(null);
-    //api_display_tool_title($nameTools);
+    Display :: display_header(null);    
 }
 
 /* Is the user allowed here? */
@@ -145,14 +144,14 @@ if ($origin == 'learnpath') {
 // The only exception is the course manager
 // I have split this is several pieces for clarity.
 //if (!api_is_allowed_to_edit() AND (($current_forum_category['visibility'] == 0 OR $current_forum['visibility'] == 0) OR ($current_forum_category['locked'] <> 0 OR $current_forum['locked'] <> 0 OR $current_thread['locked'] <> 0))) {
-if (!api_is_allowed_to_edit(null, true) AND (($current_forum_category['visibility'] == 0 OR $current_forum['visibility'] == 0))) {
+if (!api_is_allowed_to_edit(null, true) AND (($current_forum_category && $current_forum_category['visibility'] == 0) OR $current_forum['visibility'] == 0)) {
     $forum_allow = forum_not_allowed_here();
     if ($forum_allow === false) {
         exit;
     }
 }
  
-if (!api_is_allowed_to_edit(null, true) AND ($current_forum_category['locked'] <> 0 OR $current_forum['locked'] <> 0 OR $current_thread['locked'] <> 0)) {
+if (!api_is_allowed_to_edit(null, true) AND (($current_forum_category && $current_forum_category['locked'] <> 0 ) OR $current_forum['locked'] <> 0 OR $current_thread['locked'] <> 0)) {
     $forum_allow = forum_not_allowed_here();
     if ($forum_allow === false) {
         exit;
diff --git a/main/forum/forumfunction.inc.php b/main/forum/forumfunction.inc.php
index 3dc0287e14..7bac6e062d 100644
--- a/main/forum/forumfunction.inc.php
+++ b/main/forum/forumfunction.inc.php
@@ -2967,7 +2967,7 @@ function send_notification_mails($thread_id, $reply_info) {
     $current_thread	= get_thread_information($thread_id);
     $current_forum	= get_forum_information($current_thread['forum_id']);
     $current_forum_category = get_forumcategory_information($current_forum['forum_category']);
-    if ($current_thread['visibility'] == '1' && $current_forum['visibility'] == '1' && $current_forum_category['visibility'] == '1' && $current_forum['approval_direct_post'] != '1') {
+    if ($current_thread['visibility'] == '1' && $current_forum['visibility'] == '1' && ($current_forum_category && $current_forum_category['visibility'] == '1') && $current_forum['approval_direct_post'] != '1') {
         $send_mails = true;
     } else {
         $send_mails = false;
diff --git a/main/forum/forumqualify.php b/main/forum/forumqualify.php
old mode 100755
new mode 100644
index 0f6c607f8f..0ab4d9b695
--- a/main/forum/forumqualify.php
+++ b/main/forum/forumqualify.php
@@ -155,7 +155,7 @@ if ($message<>'PostDeletedSpecial') {// in this case the first and only post of
     echo '</div>';*/
     // the reply to thread link should only appear when the forum_category is not locked AND the forum is not locked AND the thread is not locked.
     // if one of the three levels is locked then the link should not be displayed
-    if ($current_forum_category['locked']==0 AND $current_forum['locked']==0 AND $current_thread['locked']==0 OR api_is_allowed_to_edit(false,true)) {
+    if (($current_forum_category && $current_forum_category['locked']==0) AND $current_forum['locked']==0 AND $current_thread['locked']==0 OR api_is_allowed_to_edit(false,true)) {
         // The link should only appear when the user is logged in or when anonymous posts are allowed.
         if ($_user['user_id'] OR ($current_forum['allow_anonymous']==1 AND !$_user['user_id'])) {
             //reply link
diff --git a/main/forum/newthread.php b/main/forum/newthread.php
index cbad196ef8..f138c29c3b 100644
--- a/main/forum/newthread.php
+++ b/main/forum/newthread.php
@@ -101,11 +101,11 @@ if (!empty($_GET['gidReq'])) {
 // 4. anonymous posts are not allowed and the user is not logged in
 // I have split this is several pieces for clarity.
 
-if (!api_is_allowed_to_edit(false, true) && (($current_forum_category['visibility'] == 0 || $current_forum['visibility'] == 0))) {
+if (!api_is_allowed_to_edit(false, true) && (($current_forum_category['visibility'] && $current_forum_category['visibility'] == 0) || $current_forum['visibility'] == 0)) {
     api_not_allowed();
 }
 // 2. the forumcategory or forum is locked (locked <>0) and the user is not a course manager
-if (!api_is_allowed_to_edit(false, true) AND ($current_forum_category['locked'] <> 0 OR $current_forum['locked'] <> 0)) {
+if (!api_is_allowed_to_edit(false, true) AND (($current_forum_category['visibility'] && $current_forum_category['locked'] <> 0) OR $current_forum['locked'] <> 0)) {
     api_not_allowed();
 }
 // 3. new threads are not allowed and the user is not a course manager
diff --git a/main/forum/viewforumcategory.php b/main/forum/viewforumcategory.php
index d229ed57b2..c1fe21ffda 100644
--- a/main/forum/viewforumcategory.php
+++ b/main/forum/viewforumcategory.php
@@ -109,11 +109,8 @@ $whatsnew_post_info = $_SESSION['whatsnew_post_info'];
 
 // if the user is not a course administrator and the forum is hidden
 // then the user is not allowed here.
-if (!api_is_allowed_to_edit(false,true) AND $current_forum_category['visibility']==0) {
-    $forum_allow = forum_not_allowed_here();
-    if ($forum_allow === false) {
-        exit;
-    }
+if (!api_is_allowed_to_edit(false,true) AND ($current_forum_category && $current_forum_category['visibility']==0)) {
+    api_not_allowed();
 }
 
 /* Action Links */
diff --git a/main/forum/viewpost.php b/main/forum/viewpost.php
old mode 100755
new mode 100644
index 895e10721c..e96fcc2c1d
--- a/main/forum/viewpost.php
+++ b/main/forum/viewpost.php
@@ -118,7 +118,7 @@ if ($message != 'PostDeletedSpecial') { // In this case the first and only post
     echo '</div>';
     // The reply to thread link should only appear when the forum_category is not locked AND the forum is not locked AND the thread is not locked.
     // If one of the three levels is locked then the link should not be displayed.
-    if ($current_forum_category['locked'] == 0 AND $current_forum['locked'] == 0 AND $current_thread['locked'] == 0 OR api_is_allowed_to_edit(false, true)) {
+    if (($current_forum_category && $current_forum_category['locked'] == 0) AND $current_forum['locked'] == 0 AND $current_thread['locked'] == 0 OR api_is_allowed_to_edit(false, true)) {
         // The link should only appear when the user is logged in or when anonymous posts are allowed.
         if ($_user['user_id'] OR ($current_forum['allow_anonymous'] == 1 AND !$_user['user_id'])) {
             // reply link
diff --git a/main/forum/viewthread.php b/main/forum/viewthread.php
index b908db49de..d1e97e258f 100644
--- a/main/forum/viewthread.php
+++ b/main/forum/viewthread.php
@@ -147,7 +147,7 @@ if ($my_message != 'PostDeletedSpecial') {
     }
     // The reply to thread link should only appear when the forum_category is not locked AND the forum is not locked AND the thread is not locked.
     // If one of the three levels is locked then the link should not be displayed.
-    if ($current_forum_category['locked'] == 0 AND $current_forum['locked'] == 0 AND $current_thread['locked'] == 0 OR api_is_allowed_to_edit(false, true)) {
+    if (($current_forum_category && $current_forum_category['locked'] == 0) AND $current_forum['locked'] == 0 AND $current_thread['locked'] == 0 OR api_is_allowed_to_edit(false, true)) {
         // The link should only appear when the user is logged in or when anonymous posts are allowed.
         if ($_user['user_id'] OR ($current_forum['allow_anonymous'] == 1 AND !$_user['user_id'])) {
             // reply link
diff --git a/main/forum/viewthread_flat.inc.php b/main/forum/viewthread_flat.inc.php
index a33dc5cb25..691fadd04f 100644
--- a/main/forum/viewthread_flat.inc.php
+++ b/main/forum/viewthread_flat.inc.php
@@ -92,7 +92,7 @@ if (isset($current_thread['thread_id'])){
             }
         }
         //echo '<br /><br />';
-        if ($current_forum_category['locked']==0 AND $current_forum['locked']==0 AND $current_thread['locked']==0 OR api_is_allowed_to_edit(false,true)) {
+        if (($current_forum_category && $current_forum_category['locked']==0) AND $current_forum['locked']==0 AND $current_thread['locked']==0 OR api_is_allowed_to_edit(false,true)) {
             if ($_user['user_id'] OR ($current_forum['allow_anonymous']==1 AND !$_user['user_id'])) {
                 if (!api_is_anonymous() && api_is_allowed_to_session_edit(false,true)) {
                     echo '<a href="reply.php?'.api_get_cidreq().'&amp;gidReq='.Security::remove_XSS($_GET['gidReq']).'&amp;forum='.$clean_forum_id.'&amp;thread='.$clean_thread_id.'&amp;post='.$row['post_id'].'&amp;action=replymessage&amp;origin='.$origin.'">'.Display :: return_icon('message_reply_forum.png', get_lang('ReplyToMessage'))."</a>";
@@ -100,7 +100,7 @@ if (isset($current_thread['thread_id'])){
                 }
             }
         } else {
-            if ($current_forum_category['locked']==1) {
+            if ($current_forum_category && $current_forum_category['locked']==1) {
                 echo get_lang('ForumcategoryLocked').'<br />';
             }
             if ($current_forum['locked']==1) {
diff --git a/main/forum/viewthread_nested.inc.php b/main/forum/viewthread_nested.inc.php
index 8b0d235015..d6c39052e8 100644
--- a/main/forum/viewthread_nested.inc.php
+++ b/main/forum/viewthread_nested.inc.php
@@ -91,7 +91,7 @@ foreach ($rows as $post) {
     }
     //echo '<br /><br />';
     //if (($current_forum_category['locked']==0 AND $current_forum['locked']==0 AND $current_thread['locked']==0) OR api_is_allowed_to_edit())
-    if ($current_forum_category['locked']==0 AND $current_forum['locked']==0 AND $current_thread['locked']==0 OR api_is_allowed_to_edit(false,true)) {
+    if (($current_forum_category && $current_forum_category['locked']==0) AND $current_forum['locked']==0 AND $current_thread['locked']==0 OR api_is_allowed_to_edit(false,true)) {
         if ($_user['user_id'] OR ($current_forum['allow_anonymous']==1 AND !$_user['user_id'])) {
             if (!api_is_anonymous() && api_is_allowed_to_session_edit(false,true)) {
                 echo '<a href="reply.php?'.api_get_cidreq().'&amp;gidReq='.Security::remove_XSS($_GET['gidReq']).'&amp;forum='.$clean_forum_id.'&amp;thread='.$clean_thread_id.'&amp;post='.$post['post_id'].'&amp;action=replymessage&amp;origin='. $origin .'">'.Display :: return_icon('message_reply_forum.png', get_lang('ReplyToMessage'))."</a>";
@@ -99,7 +99,7 @@ foreach ($rows as $post) {
             }
         }
     } else {
-        if ($current_forum_category['locked']==1) {
+        if ($current_forum_category && $current_forum_category['locked']==1) {
             echo get_lang('ForumcategoryLocked').'<br />';
         }
         if ($current_forum['locked']==1) {
diff --git a/main/forum/viewthread_threaded.inc.php b/main/forum/viewthread_threaded.inc.php
index 91d4b66a54..b47d7e80ca 100644
--- a/main/forum/viewthread_threaded.inc.php
+++ b/main/forum/viewthread_threaded.inc.php
@@ -213,7 +213,7 @@ if (api_is_allowed_to_edit(null,true)) {
 }
 //echo '<br /><br />';
 //if (($current_forum_category['locked']==0 AND $current_forum['locked']==0 AND $current_thread['locked']==0) OR api_is_allowed_to_edit())
-if ($current_forum_category['locked']==0 AND $current_forum['locked']==0 AND $current_thread['locked']==0 OR api_is_allowed_to_edit(false,true)) {
+if (($current_forum_category && $current_forum_category['locked']==0) AND $current_forum['locked']==0 AND $current_thread['locked']==0 OR api_is_allowed_to_edit(false,true)) {
     if ($_user['user_id'] OR ($current_forum['allow_anonymous']==1 AND !$_user['user_id'])) {
         if (!api_is_anonymous() && api_is_allowed_to_session_edit(false,true)) {
             echo '<a href="reply.php?'.api_get_cidreq().'&amp;gidReq='.Security::remove_XSS($_GET['gidReq']).'&amp;forum='.$clean_forum_id.'&amp;thread='.$clean_thread_id.'&amp;post='.$rows[$display_post_id]['post_id'].'&amp;action=replymessage&amp;origin='. $origin .'">'.Display :: return_icon('message_reply_forum.png', get_lang('ReplyToMessage'))."</a>";
@@ -221,7 +221,7 @@ if ($current_forum_category['locked']==0 AND $current_forum['locked']==0 AND $cu
         }
     }
 } else {
-    if ($current_forum_category['locked']==1) {
+    if ($current_forum_category && $current_forum_category['locked']==1) {
         echo get_lang('ForumcategoryLocked').'<br />';
     }
     if ($current_forum['locked']==1) {