diff --git a/client/commonFramework/end.js b/client/commonFramework/end.js
index 34a0985d2a..1c4a739a5b 100644
--- a/client/commonFramework/end.js
+++ b/client/commonFramework/end.js
@@ -7,6 +7,7 @@ $(document).ready(function() {
     init($);
   });
 
+  // only run if editor present
   if (common.editor.getValue) {
     const code$ = common.editorKeyUp$
       .debounce(750)
@@ -24,8 +25,12 @@ $(document).ready(function() {
       );
 
     code$
+      // only run for HTML
+      .filter(() => common.challengeType === challengeTypes.HTML)
       .flatMap(code => {
-        if (common.hasJs(code)) {
+        if (
+          common.hasJs(code)
+        ) {
           return common.detectUnsafeCode$(code)
             .flatMap(code => common.detectLoops$(code))
             .flatMap(
@@ -44,6 +49,7 @@ $(document).ready(function() {
         },
         err => console.error(err)
       );
+
   }
 
   common.resetBtn$
@@ -129,21 +135,24 @@ $(document).ready(function() {
   }
 
   if (
-    challengeType === challengeTypes.BONFIRE &&
+    challengeType === challengeTypes.BONFIRE ||
     challengeType === challengeTypes.JS
   ) {
     Observable.just({})
       .delay(500)
       .flatMap(() => common.executeChallenge$())
+      .catch(err => Observable.just({ err }))
       .subscribe(
-        ({ original, tests }) => {
+        ({ err, original, tests }) => {
+          if (err) {
+            console.error(err);
+            return common.updateOutputDisplay('' + err);
+          }
           common.codeStorage.updateStorage(challengeName, original);
           common.displayTestResults(tests);
         },
-        ({ err }) => {
-          if (err.stack) {
-            console.error(err);
-          }
+        (err) => {
+          console.error(err);
           common.updateOutputDisplay('' + err);
         }
       );
diff --git a/client/commonFramework/execute-challenge-stream.js b/client/commonFramework/execute-challenge-stream.js
index d9a7be1c59..de7e102751 100644
--- a/client/commonFramework/execute-challenge-stream.js
+++ b/client/commonFramework/execute-challenge-stream.js
@@ -57,12 +57,12 @@ window.common = (function(global) {
 
         // js challenge
         // remove comments and add tests to string
-        return common.addTestsToString(Object.assign(
+        return Observable.just(common.addTestsToString(Object.assign(
           {
             code: common.removeComments(code),
             tests: common.tests.slice()
           }
-        ))
+        )))
         .flatMap(common.detectLoops$)
         .flatMap(({ err, code, data, userTests }) => {
             if (err) {