diff --git a/src/js/background/assignManager.js b/src/js/background/assignManager.js
index 479c4b5..58965c8 100644
--- a/src/js/background/assignManager.js
+++ b/src/js/background/assignManager.js
@@ -712,8 +712,7 @@ async function reconcileIdentitiesByName(inSync){
   const cookieStoreIDmap = inSync.cookieStoreIDmap;
   for (const syncIdentity of inSync.identities) {
     syncIdentity.macAddonUUID = cookieStoreIDmap[syncIdentity.cookieStoreId];
-    const compareNames = function (localIdentity) { return (localIdentity.name === syncIdentity.name); };
-    const match = localIdentities.find(compareNames);
+    const match = localIdentities.find(localIdentity => localIdentity.name === syncIdentity.name);
     if (!match) {
       console.log("create new ident: ", syncIdentity.name)
       newIdentity = await browser.contextualIdentities.create({name: syncIdentity.name, color: syncIdentity.color, icon: syncIdentity.icon});
diff --git a/src/js/background/identityState.js b/src/js/background/identityState.js
index 7ccae7c..8db6cf1 100644
--- a/src/js/background/identityState.js
+++ b/src/js/background/identityState.js
@@ -67,12 +67,17 @@ const identityState = {
 
     return this.storageArea.set(cookieStoreId, containerState);
   },
+
   async updateUUID(cookieStoreId, uuid) {
-    const containerState = await this.storageArea.get(cookieStoreId);
-    containerState.macAddonUUID = uuid;
-    await this.storageArea.set(cookieStoreId, containerState);
-    return;
+    if (cookieStoreId && uuid) {
+      const containerState = await this.storageArea.get(cookieStoreId);
+      containerState.macAddonUUID = uuid;
+      await this.storageArea.set(cookieStoreId, containerState);
+      return;
+    } 
+    throw new Error ("cookieStoreId or uuid missing");
   },
+
   async addUUID(cookieStoreId) {
     return await this.updateUUID(cookieStoreId, uuidv4());
   },