diff --git a/main/exercice/exercice_submit.php b/main/exercice/exercice_submit.php
index 6779804469..7bc3416173 100755
--- a/main/exercice/exercice_submit.php
+++ b/main/exercice/exercice_submit.php
@@ -166,6 +166,9 @@ if ($origin == 'builder') {
     }
 }
 
+$course_code = api_get_course_id();
+$session_id  = api_get_session_id();
+
 $safe_lp_id = ($learnpath_id == '') ? 0 : (int) $learnpath_id;
 $safe_lp_item_id = ($learnpath_item_id == '') ? 0 : (int) $learnpath_item_id;
 $condition = ' WHERE ' .
@@ -175,7 +178,7 @@ $condition = ' WHERE ' .
     'status = ' . "'incomplete'" . ' AND ' .
     'orig_lp_id = ' . "'" . $safe_lp_id . "'" . ' AND ' .
     'orig_lp_item_id = ' . "'" . $safe_lp_item_id . "'" . ' AND ' .
-    'session_id = ' . "'" . (int) $_SESSION['id_session'] . "'";
+    'session_id = ' . "'" . (int) $session_id . "'";
 
 $TBL_EXERCICES = Database :: get_course_table(TABLE_QUIZ_TEST);
 $sql_track_exercice = "SELECT type,feedback_type,expired_time FROM $TBL_EXERCICES WHERE id=$exerciseId";
@@ -196,9 +199,11 @@ $total_minutes = $exercise_row["expired_time"];
 $total_seconds = $total_minutes*60;
 $current_timestamp = time();
 
+$current_expired_time_key = $course_code.'_'.$session_id.'_'.$exerciseId; 
+
 //Disable for learning path
 if ($exercise_row['expired_time'] != 0 && $origin != 'learnpath') {
-    if (!isset($_SESSION['expired_time'])) {
+    if (!isset($_SESSION['expired_time'][$current_expired_time_key])) {
         //In case that the current session php is broken
         //Timer - Get expired_time for a student
         $condition = ' WHERE ' .
@@ -206,7 +211,7 @@ if ($exercise_row['expired_time'] != 0 && $origin != 'learnpath') {
         'exe_user_id =  '."'".api_get_user_id()."'".' AND ' .
         'exe_cours_id = '."'".api_get_course_id()."'".' AND ' .
         'status = '."'incomplete'".' AND '.
-        'session_id = '."'".api_get_session_id()."'";
+        'session_id = '."'".$session_id."'";
 
         $sql_track = 'SELECT exe_id,expired_time_control FROM '.$stat_table.$condition;
         $rs_sql = Database::query($sql_track,__FILE__,__LINE__);
@@ -244,8 +249,8 @@ if ($exercise_row['expired_time'] != 0 && $origin != 'learnpath') {
             Database::query($sql_track_e_exe,__FILE__,__LINE__);
 
             //Sessions  that contain the expired time
-            $_SESSION['expired_time'] = $clock_expired_time;
-            $_SESSION['end_expired_time'] = date('M d, Y H:i:s',$expected_time);
+            $_SESSION['expired_time'][$current_expired_time_key] = $clock_expired_time;
+            $_SESSION['end_expired_time'][$current_expired_time_key] = date('M d, Y H:i:s',$expected_time);
         } else {
             $expected_time = $current_timestamp + $total_seconds;
 
@@ -253,12 +258,12 @@ if ($exercise_row['expired_time'] != 0 && $origin != 'learnpath') {
             $clock_expired_time = date('Y-m-d H:i:s',$expected_time);
 
             //Sessions  that contain the expired time
-            $_SESSION['expired_time'] = $clock_expired_time;
-            $_SESSION['end_expired_time'] = date('M d, Y H:i:s',$expected_time);
+            $_SESSION['expired_time'][$current_expired_time_key] = $clock_expired_time;
+            $_SESSION['end_expired_time'][$current_expired_time_key] = date('M d, Y H:i:s',$expected_time);
         }
 
     } else {
-        $plugin_expired_time = $_SESSION['end_expired_time'];
+        $plugin_expired_time = $_SESSION['end_expired_time'][$current_expired_time_key];
     }
 }
 
@@ -743,8 +748,8 @@ if ($formSent) {
                     //Verify if the current test is fraudulent
                     $current_time = time();
 
-                    if (isset($_SESSION['expired_time']) && $exercise_row['expired_time'] != 0) {
-                        $expired_date = $_SESSION['expired_time'];
+                    if (isset($_SESSION['expired_time'][$current_expired_time_key]) && $exercise_row['expired_time'][$exerciseId] != 0) {
+                        $expired_date = $_SESSION['expired_time'][$current_expired_time_key];
                         $expired_time = strtotime($expired_date);
 
                         //Validation in case of fraud
@@ -1040,13 +1045,12 @@ echo "<h3>" . $exerciseTitle . "</h3>";
 
 if ($exerciseAttempts > 0) {
     $user_id = api_get_user_id();
-    $course_code = api_get_course_id();
     $sql = "SELECT count(*) FROM $stat_table WHERE exe_exo_id = '$quizID'
                 AND exe_user_id = '$user_id'
                 AND status != 'incomplete'
                 AND orig_lp_id = $safe_lp_id
                 AND orig_lp_item_id = $safe_lp_item_id
-                AND exe_cours_id = '$course_code' AND session_id = '" . (int) $_SESSION['id_session'] . "'";
+                AND exe_cours_id = '$course_code' AND session_id = '" . (int) $session_id . "'";
 
     $aquery = Database::query($sql, __FILE__, __LINE__);
     $attempt = Database :: fetch_array($aquery);
@@ -1248,12 +1252,12 @@ if ($_configuration['live_exercise_tracking'] == true && $exerciseFeedbackType !
 
         if ($exerciseType == ONE_PER_PAGE) {
             $sql = "INSERT INTO $stat_table($sql_fields exe_exo_id,exe_user_id,exe_cours_id,status,session_id,data_tracking,start_date,orig_lp_id,orig_lp_item_id)
-                    VALUES($sql_fields_values '$exerciseId','" . api_get_user_id() . "','" . $_course['id'] . "','incomplete','" . api_get_session_id() . "','" . implode(',', $questionList) . "','" . date('Y-m-d H:i:s') . "',$safe_lp_id,$safe_lp_item_id)";
+                    VALUES($sql_fields_values '$exerciseId','" . api_get_user_id() . "','" . $_course['id'] . "','incomplete','" . $session_id . "','" . implode(',', $questionList) . "','" . date('Y-m-d H:i:s') . "',$safe_lp_id,$safe_lp_item_id)";
 
             Database::query($sql, __FILE__, __LINE__);
         } else {
             echo $sql = "INSERT INTO $stat_table ($sql_fields exe_exo_id,exe_user_id,exe_cours_id,status,session_id,start_date,orig_lp_id,orig_lp_item_id)
-                    VALUES($sql_fields_values '$exerciseId','" . api_get_user_id() . "','" . $_course['id'] . "','incomplete','" . api_get_session_id() . "','" . date('Y-m-d H:i:s') . "',$safe_lp_id,$safe_lp_item_id)";
+                    VALUES($sql_fields_values '$exerciseId','" . api_get_user_id() . "','" . $_course['id'] . "','incomplete','" . $session_id . "','" . date('Y-m-d H:i:s') . "',$safe_lp_id,$safe_lp_item_id)";
             Database::query($sql, __FILE__, __LINE__);
         }
 
diff --git a/main/exercice/exercise_show.php b/main/exercice/exercise_show.php
index 90d4c36fd6..debb1eabdc 100755
--- a/main/exercice/exercise_show.php
+++ b/main/exercice/exercise_show.php
@@ -95,8 +95,25 @@ $current_attempt = $_SESSION['current_exercice_attempt'][$current_user_id];
 //Is fraudulent exercice
 $current_time = time();
 
-if (isset($_SESSION['expired_time'])) { //Only for exercice of type "One page"
-	$expired_date = $_SESSION['expired_time'];
+$emailId   = $_REQUEST['email'];
+$user_name = $_REQUEST['user'];
+$test 	   = $_REQUEST['test'];
+$dt	 	   = $_REQUEST['dt'];
+$marks 	   = $_REQUEST['res'];
+$id 	   = $_REQUEST['id'];
+
+$sql_fb_type='SELECT feedback_type, exercises.id FROM '.$TBL_EXERCICES.' as exercises, '.$TBL_TRACK_EXERCICES.' as track_exercises WHERE exercises.id=track_exercises.exe_exo_id AND track_exercises.exe_id="'.Database::escape_string($id).'"';
+$res_fb_type=Database::query($sql_fb_type,__FILE__,__LINE__);
+$row_fb_type=Database::fetch_row($res_fb_type);
+$feedback_type = $row_fb_type[0];
+$exercise_id = intval($row_fb_type[1]);
+
+$course_code = api_get_course_id();
+$session_id  = api_get_session_id();
+$current_expired_time_key = $course_code.'_'.$session_id.'_'.$exercise_id;
+
+if (isset($_SESSION['expired_time'][$current_expired_time_key])) { //Only for exercice of type "One page"
+	$expired_date = $_SESSION['expired_time'][$current_expired_time_key];
 	$expired_time = strtotime($expired_date);
 
 	//Validation in case of fraud
@@ -106,10 +123,11 @@ if (isset($_SESSION['expired_time'])) { //Only for exercice of type "One page"
 	  Database::query($sql_fraud,__FILE__,__LINE__);
 	}
 }
+
 //Unset session for clock time
 unset($_SESSION['current_exercice_attempt'][$current_user_id]);
-unset($_SESSION['expired_time']);
-unset($_SESSION['end_expired_time']);
+unset($_SESSION['expired_time'][$current_expired_time_key]);
+unset($_SESSION['end_expired_time'][$current_expired_time_key]);
 
 $is_allowedToEdit=api_is_allowed_to_edit(null,true) || $is_courseTutor;
 $nameTools=get_lang('CorrectTest');
@@ -157,17 +175,6 @@ if ($origin != 'learnpath') {
 } else {
 	Display::display_reduced_header();
 }
-$emailId   = $_REQUEST['email'];
-$user_name = $_REQUEST['user'];
-$test 	   = $_REQUEST['test'];
-$dt	 	   = $_REQUEST['dt'];
-$marks 	   = $_REQUEST['res'];
-$id 	   = $_REQUEST['id'];
-
-$sql_fb_type='SELECT feedback_type FROM '.$TBL_EXERCICES.' as exercises, '.$TBL_TRACK_EXERCICES.' as track_exercises WHERE exercises.id=track_exercises.exe_exo_id AND track_exercises.exe_id="'.Database::escape_string($id).'"';
-$res_fb_type=Database::query($sql_fb_type,__FILE__,__LINE__);
-$row_fb_type=Database::fetch_row($res_fb_type);
-$feedback_type = $row_fb_type[0];
 
 ?>
 <style type="text/css">
diff --git a/main/inc/lib/events.lib.inc.php b/main/inc/lib/events.lib.inc.php
index 2cfb10c307..f4f13c250b 100755
--- a/main/inc/lib/events.lib.inc.php
+++ b/main/inc/lib/events.lib.inc.php
@@ -397,11 +397,13 @@ function event_link($link_id)
 function update_event_exercice($exeid,$exo_id, $score, $weighting,$session_id,$learnpath_id=0,$learnpath_item_id=0, $duration)
 {
 	if ($exeid!='') {
-
+		
 		// Validation in case of fraud with actived control time
-	    if (isset($_SESSION['expired_time'])) { //Only for exercice of type "One page"
+		$course_code = api_get_course_id();		
+		$current_expired_time_key = $course_code.'_'.$session_id.'_'.$exeid;
+	    if (isset($_SESSION['expired_time'][$current_expired_time_key])) { //Only for exercice of type "One page"
 	    	$current_time = time();
-	    	$expired_date = $_SESSION['expired_time'];
+	    	$expired_date = $_SESSION['expired_time'][$current_expired_time_key];
 	    	$expired_time = strtotime($expired_date);	    	
 	    	$total_time_allowed = $expired_time + 30;
 		    if ($total_time_allowed < $current_time) {
@@ -433,7 +435,7 @@ function update_event_exercice($exeid,$exo_id, $score, $weighting,$session_id,$l
 				 WHERE exe_id = '".Database::escape_string($exeid)."'";
 		
 		$res = @Database::query($sql,__FILE__,__LINE__);
-		unset($_SESSION['expired_time']);
+		unset($_SESSION['expired_time'][$current_expired_time_key]);
 		return $res;
 	} else
 		return false;
@@ -450,6 +452,7 @@ function create_event_exercice($exo_id)
 {
 	global $_user, $_cid, $_configuration;
 	$TABLETRACK_EXERCICES = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
+	$TBL_EXERCICES = Database::get_course_table(TABLE_QUIZ);
 	$reallyNow = time();
 	if (isset($_user['user_id']) && $_user['user_id']!='') {
 		$user_id = "'".$_user['user_id']."'";
@@ -469,8 +472,19 @@ function create_event_exercice($exo_id)
 		$row = Database::fetch_array($sql);
 		return $row['exe_id'];
 	}
-    if (isset($_SESSION['expired_time'])) { //Only for exercice of type "One page"
-    	$expired_date = $_SESSION['expired_time'];
+	// get exercise id
+	$sql_exe_id='SELECT exercises.id FROM '.$TBL_EXERCICES.' as exercises, '.$TABLETRACK_EXERCICES.' as track_exercises WHERE exercises.id=track_exercises.exe_exo_id AND track_exercises.exe_id="'.Database::escape_string($exo_id).'"';
+	$res_exe_id=Database::query($sql_exe_id,__FILE__,__LINE__);
+	$row_exe_id=Database::fetch_row($res_exe_id);
+	$exercise_id = intval($row_exe_id[0]);
+	
+	// get expired_date
+	$course_code = api_get_course_id();
+	$session_id  = api_get_session_id();
+	$current_expired_time_key = $course_code.'_'.$session_id.'_'.$exercise_id;
+		
+    if (isset($_SESSION['expired_time'][$current_expired_time_key])) { //Only for exercice of type "One page"
+    	$expired_date = $_SESSION['expired_time'][$current_expired_time_key];
     } else {
     	$expired_date = '0000-00-00 00:00:00';
     }
@@ -504,10 +518,13 @@ function exercise_attempt($score,$answer,$quesId,$exeId,$j)
 	global $_configuration, $_user, $_cid;
 	$TBL_TRACK_ATTEMPT = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);
 
-	//Validation in case of fraud with actived control time 
-    if (isset($_SESSION['expired_time'])) { //Only for exercice of type "One page"
+	//Validation in case of fraud with actived control time	
+	$course_code = api_get_course_id();
+	$session_id  = api_get_session_id();
+	$current_expired_time_key = $course_code.'_'.$session_id.'_'.$exeId;	 
+    if (isset($_SESSION['expired_time'][$current_expired_time_key])) { //Only for exercice of type "One page"
     	$current_time = time();
-    	$expired_date = $_SESSION['expired_time'];
+    	$expired_date = $_SESSION['expired_time'][$current_expired_time_key];
     	$expired_time = strtotime($expired_date);
 	    $total_time_allowed = $expired_time + 30;	 
 	    if ($total_time_allowed < $current_time) {
@@ -593,10 +610,15 @@ function exercise_attempt_hotspot($exe_id, $question_id, $answer_id, $correct, $
 		return 0;
 	}
 
-	//Validation in case of fraud  with actived control time   
-    if (isset($_SESSION['expired_time'])) { //Only for exercice of type "One page"
+	//Validation in case of fraud  with actived control time  
+	
+	$course_code = api_get_course_id();
+	$session_id  = api_get_session_id();
+	$current_expired_time_key = $course_code.'_'.$session_id.'_'.$exe_id;
+	 
+    if (isset($_SESSION['expired_time'][$current_expired_time_key])) { //Only for exercice of type "One page"
     	$current_time = time();
-    	$expired_date = $_SESSION['expired_time'];
+    	$expired_date = $_SESSION['expired_time'][$current_expired_time_key];
     	$expired_time = strtotime($expired_date);
     	$total_time_allowed = $expired_time + 30;
 	    if ($total_time_allowed < $current_time) {