diff --git a/application/helpers/expressions/em_core_helper.php b/application/helpers/expressions/em_core_helper.php
index 2132a415fdb..0c6255064b1 100644
--- a/application/helpers/expressions/em_core_helper.php
+++ b/application/helpers/expressions/em_core_helper.php
@@ -1668,11 +1668,22 @@ public function sProcessStringContainingExpressions($src, $questionNum = 0, $num
         $prettyPrint = '';
         $errors = array();
 
+        $prettyPrintIterationDone = false;
         for ($i = 1; $i <= $numRecursionLevels; ++$i) {
             // TODO - Since want to use <span> for dynamic substitution, what if there are recursive substititons?
+            $prevResult = $result;
             $result = $this->sProcessStringContainingExpressionsHelper($result, $questionNum, $staticReplacement);
+            if($result === $prevResult) {
+                // No update during process : can exit of iteration
+                if(!$prettyPrintIterationDone) {
+                    $prettyPrint = $this->prettyPrintSource;
+                }
+                // No need errors : already done
+                break;
+            }
             if ($i == $whichPrettyPrintIteration) {
                 $prettyPrint = $this->prettyPrintSource;
+                $prettyPrintIterationDone = true;
             }
             $errors = array_merge($errors, $this->RDP_errs);
         }
@@ -1962,10 +1973,20 @@ private function RDP_SetVariableValue($op, $name, $value)
      */
     public function asSplitStringOnExpressions($src)
     {
+        // Empty string, return an array
+        if($src === "") {
+            return array();
+        }
+        // No replacement to do, preg_split get more time than strpos
+        if(strpos($src, "{") === false || $src==="{"  || $src==="}") { 
+            return array (
+                0 => array ($src,0,'STRING')
+            );
+        };
 
+        // Seems to need split and replacement
         $parts = preg_split($this->RDP_ExpressionRegex, $src, -1, (PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE));
 
-
         $count = count($parts);
         $tokens = array();
         $inSQString = false;
diff --git a/application/helpers/expressions/em_manager_helper.php b/application/helpers/expressions/em_manager_helper.php
index df1fc714cf2..2ab528b1c27 100644
--- a/application/helpers/expressions/em_manager_helper.php
+++ b/application/helpers/expressions/em_manager_helper.php
@@ -347,12 +347,14 @@ class LimeExpressionManager {
         * current Group sequence (0-based index)
         * @example 1
         * @var integer
+        * @deprecated : not updated in this class
         */
         private $currentGroupSeq;
         /**
         * for Question-by-Question mode, the 0-based index
         * @example 3
         * @var integer
+        * @deprecated : not updated in this class
         */
         private $currentQuestionSeq;
         /**