diff --git a/main/exercise/TestCategory.php b/main/exercise/TestCategory.php
index 7de92e9196..3de809f5d7 100644
--- a/main/exercise/TestCategory.php
+++ b/main/exercise/TestCategory.php
@@ -5,6 +5,7 @@ use ChamiloSession as Session;
 
 /**
  * Class TestCategory.
+ * Manage question categories inside an exercise.
  *
  * @author hubert.borderiou
  * @author Julio Montoya - several fixes
diff --git a/main/inc/lib/api.lib.php b/main/inc/lib/api.lib.php
index 50dd40ef21..624dac6a58 100644
--- a/main/inc/lib/api.lib.php
+++ b/main/inc/lib/api.lib.php
@@ -1158,9 +1158,6 @@ function api_protect_course_script($print_headers = false, $allow_session_admins
         return false;
     }
 
-    $is_allowed_in_course = api_is_allowed_in_course();
-    $is_visible = false;
-
     if (api_is_drh()) {
         return true;
     }
@@ -1175,6 +1172,8 @@ function api_protect_course_script($print_headers = false, $allow_session_admins
         return true;
     }
 
+    $is_allowed_in_course = api_is_allowed_in_course();
+    $is_visible = false;
     if (isset($course_info) && isset($course_info['visibility'])) {
         switch ($course_info['visibility']) {
             default:
diff --git a/main/inc/lib/exercise.lib.php b/main/inc/lib/exercise.lib.php
index c4f2e5d855..99f6fbb664 100644
--- a/main/inc/lib/exercise.lib.php
+++ b/main/inc/lib/exercise.lib.php
@@ -3082,7 +3082,6 @@ EOT;
                     ICON_SIZE_MEDIUM
                 );
             } else {
-                //$html .= Display::return_message(get_lang('YouDidNotReachTheMinimumScore'), 'warning');
                 $html = get_lang('YouDidNotReachTheMinimumScore');
                 $icon = Display::return_icon(
                     'warning.png',
@@ -5034,7 +5033,7 @@ EOT;
                 $score, $weight, $objExercise->selectPassPercentage()
             );
             // Color the final test score if pass_percentage activated
-            $ribbonTotalSuccessOrError = "";
+            $ribbonTotalSuccessOrError = '';
             if (self::isPassPercentageEnabled($objExercise->selectPassPercentage())) {
                 if ($isSuccess) {
                     $ribbonTotalSuccessOrError = ' ribbon-total-success';
diff --git a/main/inc/lib/pear/HTML/Table/Storage.php b/main/inc/lib/pear/HTML/Table/Storage.php
index 3dd5d907f7..2abf60f817 100755
--- a/main/inc/lib/pear/HTML/Table/Storage.php
+++ b/main/inc/lib/pear/HTML/Table/Storage.php
@@ -470,7 +470,7 @@ class HTML_Table_Storage extends HTML_Common
      * @return   int
      * @access   public
      */
-    function addRow($contents = null, $attributes = null, $type = 'td',
+    function addRow($contents = [], $attributes = null, $type = 'td',
         $inTR = false)
     {
         if (isset($contents) && !is_array($contents)) {