diff --git a/js/helpers.js b/js/helpers.js
index 6def092..bdf0442 100644
--- a/js/helpers.js
+++ b/js/helpers.js
@@ -19,16 +19,6 @@ export function shuffleArray(array) {
   return array;
 }
 
-export function urltoFile(url, filename, mimeType) {
-  return fetch(url)
-    .then(function (res) {
-      return res.arrayBuffer();
-    })
-    .then(function (buf) {
-      return new File([buf], filename, { type: mimeType });
-    });
-}
-
 export function formatBytes(bytes, decimals = 2) {
   if (bytes === 0) return "0 Bytes";
 
diff --git a/js/main.js b/js/main.js
index c7f413b..b74612a 100644
--- a/js/main.js
+++ b/js/main.js
@@ -88,7 +88,10 @@ async function loadPacketList(data) {
     }
   });
 
-  window.packet_list = data.packets;
+  if (data != null) {
+    window.packet_list = data.packets;
+  }
+  $("#packet-list").empty();
   window.packet_list.forEach(function (packet) {
     let c = "";
     if (packets_started.indexOf(packet) > -1) {
@@ -469,7 +472,7 @@ function loadQuestion(n, section = 1, force_reload = false) {
         // otherwise try to load it as a dicom
       } else {
         // convert the data url to a file
-        helper
+        viewer
           .urltoFile(based_img, "dicom", "application/dicom")
           .then(function (dfile) {
             // load the file using cornerstoneWADO file loader
@@ -956,6 +959,7 @@ $("#review-button").click(function (evt) {
 });
 
 $("#options-button").click(function (evt) {
+  loadPacketList(null);
   $("#options-panel").toggle();
 });
 
@@ -1075,8 +1079,10 @@ function submitAnswers() {
  * Displays the review question panel with a summary of marks
  */
 function reviewQuestions() {
-  // Stop timer
+  // Stop timer (if it's running)
+  if (window.timer != null) {
   window.timer.stop();
+  }
 
   const cid = window.cid;
   const eid = window.eid;
diff --git a/js/viewer.js b/js/viewer.js
index 13bfa22..d965ad9 100644
--- a/js/viewer.js
+++ b/js/viewer.js
@@ -503,7 +503,7 @@ export function openMainImage(current_question, t, source) {
       } else if (data_url.startsWith("data:application/dicom")) {
         // stack = stack.split(";")[1];
 
-        const dfile = await helper.urltoFile(
+        const dfile = await urltoFile(
           data_url,
           "dicom",
           "application/dicom"
@@ -566,3 +566,13 @@ export function openMainImage(current_question, t, source) {
     load(images);
   }
 }
+
+export function urltoFile(url, filename, mimeType) {
+  return fetch(url)
+    .then(function (res) {
+      return res.arrayBuffer();
+    })
+    .then(function (buf) {
+      return new File([buf], filename, { type: mimeType });
+    });
+}