diff --git a/app/auto_update.js b/app/auto_update.js
index 26bc105ee..6725cf3cd 100644
--- a/app/auto_update.js
+++ b/app/auto_update.js
@@ -18,8 +18,12 @@ function autoUpdateDisabled() {
   );
 }
 
-function checkForUpdates() {
-  autoUpdater.checkForUpdates();
+async function checkForUpdates() {
+  try {
+    await autoUpdater.checkForUpdates();
+  } catch (error) {
+    console.log('checkForUpdates error:', error.stack);
+  }
 }
 
 let showingDialog = false;
@@ -58,7 +62,7 @@ function showUpdateDialog(mainWindow, messages) {
 }
 
 function onError(error) {
-  console.log('Got an error while updating: ', error.stack);
+  console.log('Got an error while updating:', error.stack);
 }
 
 function initialize(getMainWindow, messages) {
diff --git a/js/views/conversation_view.js b/js/views/conversation_view.js
index e841cb914..3d2aafb56 100644
--- a/js/views/conversation_view.js
+++ b/js/views/conversation_view.js
@@ -708,9 +708,9 @@
 
       // Look for message in memory first, which would tell us if we could scroll to it
       const targetMessage = this.model.messageCollection.find(item => {
-        const messageAuthor = item.getContact().id;
+        const messageAuthor = item.getContact();
 
-        if (author !== messageAuthor) {
+        if (!messageAuthor || author !== messageAuthor.id) {
           return false;
         }
         if (id !== item.get('sent_at')) {
diff --git a/libtextsecure/libsignal-protocol.js b/libtextsecure/libsignal-protocol.js
index b349b11c5..b5eb93b3e 100644
--- a/libtextsecure/libsignal-protocol.js
+++ b/libtextsecure/libsignal-protocol.js
@@ -25294,13 +25294,20 @@ var origCurve25519 = Internal.curve25519_async;
 
 Internal.startWorker = function(url) {
     Internal.stopWorker(); // there can be only one
+
     Internal.curve25519_async = new Curve25519Worker(url);
+    Internal.Curve.async = Internal.wrapCurve25519(Internal.curve25519_async);
+    libsignal.Curve.async = Internal.wrapCurve(Internal.Curve.async);
 };
 
 Internal.stopWorker = function() {
     if (Internal.curve25519_async instanceof Curve25519Worker) {
         var worker = Internal.curve25519_async.worker;
+
         Internal.curve25519_async = origCurve25519;
+        Internal.Curve.async = Internal.wrapCurve25519(Internal.curve25519_async);
+        libsignal.Curve.async = Internal.wrapCurve(Internal.Curve.async);
+
         worker.terminate();
     }
 };
@@ -35158,6 +35165,7 @@ Curve25519Worker.prototype = {
         };
     }
 
+    Internal.wrapCurve25519 = wrapCurve25519;
     Internal.Curve       = wrapCurve25519(Internal.curve25519);
     Internal.Curve.async = wrapCurve25519(Internal.curve25519_async);
 
@@ -35185,6 +35193,7 @@ Curve25519Worker.prototype = {
         };
     }
 
+    Internal.wrapCurve = wrapCurve;
     libsignal.Curve       = wrapCurve(Internal.Curve);
     libsignal.Curve.async = wrapCurve(Internal.Curve.async);
 
diff --git a/libtextsecure/sendmessage.js b/libtextsecure/sendmessage.js
index e42fe21e1..ab070ff55 100644
--- a/libtextsecure/sendmessage.js
+++ b/libtextsecure/sendmessage.js
@@ -108,7 +108,7 @@ Message.prototype = {
         const item = new textsecure.protobuf.DataMessage.Preview();
         item.title = preview.title;
         item.url = preview.url;
-        item.image = preview.image;
+        item.image = preview.image || null;
         return item;
       });
     }
diff --git a/main.js b/main.js
index 775e160be..a591de670 100644
--- a/main.js
+++ b/main.js
@@ -369,7 +369,9 @@ function createWindow() {
     }
 
     await requestShutdown();
-    mainWindow.readyForShutdown = true;
+    if (mainWindow) {
+      mainWindow.readyForShutdown = true;
+    }
     app.quit();
   });
 
diff --git a/package.json b/package.json
index a03e5b848..405ce470c 100644
--- a/package.json
+++ b/package.json
@@ -3,7 +3,7 @@
   "productName": "Signal",
   "description": "Private messaging from your desktop",
   "repository": "https://github.com/signalapp/Signal-Desktop.git",
-  "version": "1.21.0",
+  "version": "1.21.1-beta.1",
   "license": "GPL-3.0",
   "author": {
     "name": "Open Whisper Systems",