diff --git a/ts/components/conversation/TimerNotification.stories.tsx b/ts/components/conversation/TimerNotification.stories.tsx
index 3b19c9c298..dba47f63b7 100644
--- a/ts/components/conversation/TimerNotification.stories.tsx
+++ b/ts/components/conversation/TimerNotification.stories.tsx
@@ -103,3 +103,21 @@ export function SetBySync(args: Props): JSX.Element {
     </>
   );
 }
+
+export function SetByUnknownContact(args: Props): JSX.Element {
+  const props: Props = {
+    ...args,
+    disabled: false,
+    expireTimer: DurationInSeconds.fromHours(1),
+    type: 'fromMember',
+    title: 'Unknown contact',
+  };
+
+  return (
+    <>
+      <TimerNotification {...props} />
+      <div style={{ padding: '1em' }} />
+      <TimerNotification {...props} disabled />
+    </>
+  );
+}
diff --git a/ts/jobs/AttachmentDownloadManager.ts b/ts/jobs/AttachmentDownloadManager.ts
index 23ee4e6b30..44faa5d341 100644
--- a/ts/jobs/AttachmentDownloadManager.ts
+++ b/ts/jobs/AttachmentDownloadManager.ts
@@ -192,6 +192,16 @@ export class AttachmentDownloadManager extends JobManager<CoreAttachmentDownload
       source,
       urgency = AttachmentDownloadUrgency.STANDARD,
     } = newJobData;
+
+    const logId = `AttachmentDownloadManager/addJob(${sentAt}.${attachmentType})`;
+
+    if (attachment.error && source === AttachmentDownloadSource.BACKUP_IMPORT) {
+      log.info(
+        `${logId}: skipping InvalidAttachmentLocator from backup import`
+      );
+      return attachment;
+    }
+
     const parseResult = safeParsePartial(coreAttachmentDownloadJobSchema, {
       messageId,
       receivedAt,
@@ -213,10 +223,7 @@ export class AttachmentDownloadManager extends JobManager<CoreAttachmentDownload
     });
 
     if (!parseResult.success) {
-      log.error(
-        `AttachmentDownloadManager/addJob(${sentAt}.${attachmentType}): invalid data`,
-        parseResult.error
-      );
+      log.error(`${logId}: invalid data`, parseResult.error);
       return attachment;
     }
 
diff --git a/ts/services/backups/import.ts b/ts/services/backups/import.ts
index 35b7086644..431f4e8238 100644
--- a/ts/services/backups/import.ts
+++ b/ts/services/backups/import.ts
@@ -20,7 +20,7 @@ import {
 import * as log from '../../logging/log';
 import { GiftBadgeStates } from '../../components/conversation/Message';
 import { StorySendMode, MY_STORY_ID } from '../../types/Stories';
-import type { ServiceIdString } from '../../types/ServiceId';
+import type { AciString, ServiceIdString } from '../../types/ServiceId';
 import {
   fromAciObject,
   fromPniObject,
@@ -571,7 +571,7 @@ export class BackupImportStream extends Writable {
         );
       }
     }
-    await Promise.all(attachmentDownloadJobPromises);
+    await Promise.allSettled(attachmentDownloadJobPromises);
     await AttachmentDownloadManager.saveBatchedJobs();
   }
 
@@ -1363,6 +1363,7 @@ export class BackupImportStream extends Writable {
         sentAt -= 1;
         additionalMessages.push({
           ...attributes,
+          ...generateMessageId(incrementMessageCounter()),
           sent_at: sentAt,
           ...additional,
         });
@@ -2776,12 +2777,12 @@ export class BackupImportStream extends Writable {
       }
       if (update.groupExpirationTimerUpdate) {
         const { updaterAci, expiresInMs } = update.groupExpirationTimerUpdate;
-        if (!updaterAci || Bytes.isEmpty(updaterAci)) {
-          throw new Error(
-            `${logId}: groupExpirationTimerUpdate was missing updaterAci!`
-          );
+        let sourceServiceId: AciString | undefined;
+
+        if (Bytes.isNotEmpty(updaterAci)) {
+          sourceServiceId = fromAciObject(Aci.fromUuidBytes(updaterAci));
         }
-        const sourceServiceId = fromAciObject(Aci.fromUuidBytes(updaterAci));
+
         const expireTimer = expiresInMs
           ? DurationInSeconds.fromMillis(expiresInMs.toNumber())
           : undefined;