diff --git a/src/Calendars/Main.tsx b/src/Calendars/Main.tsx
index a49f982..c902a59 100644
--- a/src/Calendars/Main.tsx
+++ b/src/Calendars/Main.tsx
@@ -46,10 +46,8 @@ export default function CalendarsMain() {
     }
     (async () => {
       const colEntries = await decryptCollections(collections);
-      // FIXME: handle failure to decrypt collections
 
       const entries = await decryptItems(items);
-      // FIXME: handle failure to decrypt items
 
       for (const collection of colEntries) {
         const items = entries.get(collection.collection.uid)!;
diff --git a/src/Collections/CollectionChangeEntries.tsx b/src/Collections/CollectionChangeEntries.tsx
index 10dd51f..39c636a 100644
--- a/src/Collections/CollectionChangeEntries.tsx
+++ b/src/Collections/CollectionChangeEntries.tsx
@@ -66,7 +66,6 @@ export default function CollectionChangeEntries(props: PropsType) {
     if (items) {
       decryptItems(items)
         .then((entries) => setEntries(entries.get(collection.uid)));
-      // FIXME: handle failure to decrypt items
     }
   }, [items]);
 
diff --git a/src/Collections/CollectionMembers.tsx b/src/Collections/CollectionMembers.tsx
index 3e46207..735c43f 100644
--- a/src/Collections/CollectionMembers.tsx
+++ b/src/Collections/CollectionMembers.tsx
@@ -20,6 +20,7 @@ import { getCollectionManager } from "../etebase-helpers";
 import { CachedCollection } from "../Pim/helpers";
 
 import CollectionMemberAddDialog from "./CollectionMemberAddDialog";
+import Alert from "@material-ui/lab/Alert";
 
 interface PropsType {
   collection: CachedCollection;
@@ -30,15 +31,19 @@ export default function CollectionMembers(props: PropsType) {
   const [members_, setMembers] = React.useState<Etebase.CollectionMember[]>();
   const [revokeUser, setRevokeUser] = React.useState<string | null>(null);
   const [addMemberOpen, setAddMemberOpen] = React.useState(false);
-  // FIXME: add error handling
+  const [error, setError] = React.useState<Error>();
 
   const { collection, metadata } = props.collection;
 
   async function fetchMembers() {
     const colMgr = getCollectionManager(etebase);
     const memberManager = colMgr.getMemberManager(collection);
-    const members = await memberManager.list();
-    setMembers(members.data);
+    try {
+      const members = await memberManager.list();
+      setMembers(members.data);
+    } catch (e) {
+      setError(e);
+    }
   }
 
   React.useEffect(() => {
@@ -70,6 +75,11 @@ export default function CollectionMembers(props: PropsType) {
     <>
       <AppBarOverride title={`${metadata.name} - Members`} />
       <Container style={{ maxWidth: "30rem" }}>
+        {error && (
+          <Alert color="error">
+            {error.toString()}
+          </Alert>
+        )}
         {members ?
           <List>
             <ListItem rightIcon={<IconMemberAdd />} onClick={() => setAddMemberOpen(true)}>
diff --git a/src/Contacts/Main.tsx b/src/Contacts/Main.tsx
index 7b64aae..689ceca 100644
--- a/src/Contacts/Main.tsx
+++ b/src/Contacts/Main.tsx
@@ -37,16 +37,16 @@ export default function ContactsMain() {
   const items = useItems(etebase, colType);
 
   React.useEffect(() => {
-    if (items) {
-      decryptItems(items)
-        .then((entries) => setEntries(entries));
-      // FIXME: handle failure to decrypt items
-    }
-    if (collections) {
-      decryptCollections(collections)
-        .then((entries) => setCachedCollections(entries));
-      // FIXME: handle failure to decrypt collections
+    if (!collections || !items) {
+      return;
     }
+    (async () => {
+      const colEntries = await decryptCollections(collections);
+      const entries = await decryptItems(items);
+
+      setCachedCollections(colEntries);
+      setEntries(entries);
+    })();
   }, [items, collections]);
 
   if (!entries || !cachedCollections) {
diff --git a/src/Pim/helpers.tsx b/src/Pim/helpers.tsx
index d4a0f0f..6d41628 100644
--- a/src/Pim/helpers.tsx
+++ b/src/Pim/helpers.tsx
@@ -11,8 +11,8 @@ import * as Etebase from "etebase";
 
 import { PimType } from "../pim-types";
 import { getCollectionManager } from "../etebase-helpers";
-import { asyncDispatch } from "../store";
-import { itemBatch } from "../store/actions";
+import { asyncDispatch, store } from "../store";
+import { itemBatch, appendError } from "../store/actions";
 
 export const defaultColor = "#8BC34A";
 
@@ -32,10 +32,14 @@ export function getDecryptCollectionsFunction(_colType?: string) {
       const entries: CachedCollection[] = [];
       if (collections) {
         for (const collection of collections) {
-          entries.push({
-            collection,
-            metadata: await collection.getMeta(),
-          });
+          try {
+            entries.push({
+              collection,
+              metadata: await collection.getMeta(),
+            });
+          } catch (e) {
+            store.dispatch(appendError(e));
+          }
         }
       }
 
@@ -54,10 +58,14 @@ export function getDecryptItemsFunction<T extends PimType>(_colType: string, par
           const cur = new Map();
           entries.set(colUid, cur);
           for (const item of col.values()) {
-            const contact = parseFunc(await item.getContent(Etebase.OutputFormat.String));
-            contact.collectionUid = colUid;
-            contact.itemUid = item.uid;
-            cur.set(item.uid, contact);
+            try {
+              const contact = parseFunc(await item.getContent(Etebase.OutputFormat.String));
+              contact.collectionUid = colUid;
+              contact.itemUid = item.uid;
+              cur.set(item.uid, contact);
+            } catch (e) {
+              store.dispatch(appendError(e));
+            }
           }
         }
       }
diff --git a/src/Tasks/Main.tsx b/src/Tasks/Main.tsx
index 6276aec..645167f 100644
--- a/src/Tasks/Main.tsx
+++ b/src/Tasks/Main.tsx
@@ -37,16 +37,16 @@ export default function TasksMain() {
   const items = useItems(etebase, colType);
 
   React.useEffect(() => {
-    if (items) {
-      decryptItems(items)
-        .then((entries) => setEntries(entries));
-      // FIXME: handle failure to decrypt items
-    }
-    if (collections) {
-      decryptCollections(collections)
-        .then((entries) => setCachedCollections(entries));
-      // FIXME: handle failure to decrypt collections
+    if (!collections || !items) {
+      return;
     }
+    (async () => {
+      const colEntries = await decryptCollections(collections);
+      const entries = await decryptItems(items);
+
+      setCachedCollections(colEntries);
+      setEntries(entries);
+    })();
   }, [items, collections]);
 
   if (!entries || !cachedCollections) {
diff --git a/src/store/actions.ts b/src/store/actions.ts
index 29df131..9e2ec39 100644
--- a/src/store/actions.ts
+++ b/src/store/actions.ts
@@ -168,7 +168,7 @@ export const performSync = createAction(
 
 export const appendError = createAction(
   "APPEND_ERROR",
-  (_etesync: Etebase.Account, error: Error | Error[]) => {
+  (error: Error | Error[]) => {
     return Array.isArray(error) ? error : [error];
   }
 );
diff --git a/src/sync/SyncManager.ts b/src/sync/SyncManager.ts
index f1c3357..b02baab 100644
--- a/src/sync/SyncManager.ts
+++ b/src/sync/SyncManager.ts
@@ -6,7 +6,7 @@ import * as Etebase from "etebase";
 import { store, StoreState } from "../store";
 
 import { credentialsSelector } from "../credentials";
-import { setSyncCollection, setSyncGeneral, setCacheCollection, unsetCacheCollection, setCacheItemMulti } from "../store/actions";
+import { setSyncCollection, setSyncGeneral, setCacheCollection, unsetCacheCollection, setCacheItemMulti, appendError } from "../store/actions";
 
 const cachedSyncManager = new Map<string, SyncManager>();
 export class SyncManager {
@@ -105,7 +105,7 @@ export class SyncManager {
           case 401: // INVALID TOKEN
           case 403: // FORBIDDEN
           case 503: // UNAVAILABLE
-            // FIXME store.dispatch(addNonFatalError(this.etebase, e));
+            store.dispatch(appendError(e));
             return null;
         }
       }