diff --git a/lib/shared/dm-ops/process-dm-ops.js b/lib/shared/dm-ops/process-dm-ops.js
index 3cacf29c4..b193d565d 100644
--- a/lib/shared/dm-ops/process-dm-ops.js
+++ b/lib/shared/dm-ops/process-dm-ops.js
@@ -1,404 +1,426 @@
 // @flow
 
 import invariant from 'invariant';
 import _groupBy from 'lodash/fp/groupBy.js';
 import * as React from 'react';
 import uuid from 'uuid';
 
 import type { ProcessDMOperationUtilities } from './dm-op-spec.js';
 import { dmOpSpecs } from './dm-op-specs.js';
 import {
   type OutboundDMOperationSpecification,
   type DMOperationSpecification,
   createMessagesToPeersFromDMOp,
   dmOperationSpecificationTypes,
   type OutboundComposableDMOperationSpecification,
 } from './dm-op-utils.js';
 import { processNewUserIDsActionType } from '../../actions/user-actions.js';
 import { useLoggedInUserInfo } from '../../hooks/account-hooks.js';
 import { useGetLatestMessageEdit } from '../../hooks/latest-message-edit.js';
 import { useDispatchWithMetadata } from '../../hooks/ops-hooks.js';
 import { mergeUpdatesWithMessageInfos } from '../../reducers/message-reducer.js';
 import { getAllPeerUserIDAndDeviceIDs } from '../../selectors/user-selectors.js';
 import {
   usePeerToPeerCommunication,
   type ProcessOutboundP2PMessagesResult,
 } from '../../tunnelbroker/peer-to-peer-context.js';
 import {
   processDMOpsActionType,
   queueDMOpsActionType,
   dmOperationValidator,
 } from '../../types/dm-ops.js';
 import type { RawThreadInfo } from '../../types/minimally-encoded-thread-permissions-types.js';
 import type { DispatchMetadata } from '../../types/redux-types.js';
 import type { OutboundP2PMessage } from '../../types/sqlite-types.js';
 import type { LegacyRawThreadInfo } from '../../types/thread-types.js';
 import { updateTypes } from '../../types/update-types-enum.js';
 import { extractUserIDsFromPayload } from '../../utils/conversion-utils.js';
 import { useSelector, useDispatch } from '../../utils/redux-utils.js';
 import { messageSpecs } from '../messages/message-specs.js';
 import { updateSpecs } from '../updates/update-specs.js';
 
 function useSendDMOperationUtils(): ProcessDMOperationUtilities {
   const fetchMessage = useGetLatestMessageEdit();
   const threadInfos = useSelector(state => state.threadStore.threadInfos);
   const entryInfos = useSelector(state => state.entryStore.entryInfos);
   return React.useMemo(
     () => ({
       fetchMessage,
       threadInfos,
       entryInfos,
     }),
     [fetchMessage, threadInfos, entryInfos],
   );
 }
 
 function useProcessDMOperation(): (
   dmOperationSpecification: DMOperationSpecification,
   dmOpID: ?string,
 ) => Promise<void> {
   const threadInfos = useSelector(state => state.threadStore.threadInfos);
   const utilities = useSendDMOperationUtils();
   const dispatchWithMetadata = useDispatchWithMetadata();
   const loggedInUserInfo = useLoggedInUserInfo();
   const viewerID = loggedInUserInfo?.id;
   const allPeerUserIDAndDeviceIDs = useSelector(getAllPeerUserIDAndDeviceIDs);
   const currentUserInfo = useSelector(state => state.currentUserInfo);
 
   const dispatch = useDispatch();
 
   return React.useCallback(
     async (
       dmOperationSpecification: DMOperationSpecification,
       dmOpID: ?string,
     ) => {
       if (!viewerID) {
         console.log('ignored DMOperation because logged out');
         return;
       }
 
       const { op: dmOp } = dmOperationSpecification;
 
       let outboundP2PMessages: ?$ReadOnlyArray<OutboundP2PMessage> = null;
       if (
         dmOperationSpecification.type === dmOperationSpecificationTypes.OUTBOUND
       ) {
         outboundP2PMessages = await createMessagesToPeersFromDMOp(
           dmOp,
           dmOperationSpecification.recipients,
           allPeerUserIDAndDeviceIDs,
           currentUserInfo,
           threadInfos,
         );
       }
 
       let dispatchMetadata: ?DispatchMetadata = null;
       if (
         dmOperationSpecification.type ===
           dmOperationSpecificationTypes.OUTBOUND &&
         dmOpID
       ) {
         dispatchMetadata = {
           dmOpID,
         };
       } else if (
         dmOperationSpecification.type === dmOperationSpecificationTypes.INBOUND
       ) {
         dispatchMetadata = dmOperationSpecification.metadata;
       }
 
       let composableMessageID: ?string = null;
       if (
         dmOperationSpecification.type ===
           dmOperationSpecificationTypes.OUTBOUND &&
         !dmOpSpecs[dmOp.type].supportsAutoRetry
       ) {
         composableMessageID = dmOp.messageID;
       }
 
       if (
         dmOperationSpecification.type ===
           dmOperationSpecificationTypes.OUTBOUND &&
         dmOperationSpecification.sendOnly
       ) {
         const notificationsCreationData = await dmOpSpecs[
           dmOp.type
         ].notificationsCreationData?.(dmOp, utilities);
 
         dispatchWithMetadata(
           {
             type: processDMOpsActionType,
             payload: {
               rawMessageInfos: [],
               updateInfos: [],
               outboundP2PMessages,
               composableMessageID,
               notificationsCreationData,
             },
           },
           dispatchMetadata,
         );
 
         return;
       }
 
       const processingCheckResult = dmOpSpecs[dmOp.type].canBeProcessed(
         dmOp,
         viewerID,
         utilities,
       );
       if (!processingCheckResult.isProcessingPossible) {
         if (processingCheckResult.reason.type === 'missing_thread') {
           dispatchWithMetadata(
             {
               type: queueDMOpsActionType,
               payload: {
                 operation: dmOp,
                 threadID: processingCheckResult.reason.threadID,
                 timestamp: Date.now(),
               },
             },
             dispatchMetadata,
           );
         }
         return;
       }
 
       const newUserIDs = extractUserIDsFromPayload(dmOperationValidator, dmOp);
       if (newUserIDs.length > 0) {
         dispatch({
           type: processNewUserIDsActionType,
           payload: { userIDs: newUserIDs },
         });
       }
 
       const dmOpSpec = dmOpSpecs[dmOp.type];
       const notificationsCreationDataPromise = (async () => {
         return await dmOpSpec.notificationsCreationData?.(dmOp, utilities);
       })();
 
       const [{ rawMessageInfos, updateInfos }, notificationsCreationData] =
         await Promise.all([
           dmOpSpec.processDMOperation(dmOp, viewerID, utilities),
           notificationsCreationDataPromise,
         ]);
 
       const { rawMessageInfos: allNewMessageInfos } =
         mergeUpdatesWithMessageInfos(rawMessageInfos, updateInfos);
       const messagesByThreadID = _groupBy(message => message.threadID)(
         allNewMessageInfos,
       );
 
       const updatedThreadInfosByThreadID: {
         [string]: RawThreadInfo | LegacyRawThreadInfo,
       } = {};
       for (const threadID in messagesByThreadID) {
         updatedThreadInfosByThreadID[threadID] = threadInfos[threadID];
       }
       for (const update of updateInfos) {
         const updatedThreadInfo = updateSpecs[
           update.type
         ].getUpdatedThreadInfo?.(update, updatedThreadInfosByThreadID);
         if (updatedThreadInfo) {
           updatedThreadInfosByThreadID[updatedThreadInfo.id] =
             updatedThreadInfo;
         }
       }
 
       for (const threadID in messagesByThreadID) {
         const repliesCountIncreasingMessages = messagesByThreadID[
           threadID
         ].filter(message => messageSpecs[message.type].includedInRepliesCount);
 
         const threadInfo = updatedThreadInfosByThreadID[threadID];
 
         if (repliesCountIncreasingMessages.length > 0) {
           const repliesCountIncreaseTime = Math.max(
             repliesCountIncreasingMessages.map(message => message.time),
           );
           updateInfos.push({
             type: updateTypes.UPDATE_THREAD,
             id: uuid.v4(),
             time: repliesCountIncreaseTime,
             threadInfo: {
               ...threadInfo,
               repliesCount:
                 threadInfo.repliesCount + repliesCountIncreasingMessages.length,
             },
           });
         }
 
         const messagesFromOtherPeers = messagesByThreadID[threadID].filter(
           message => message.creatorID !== viewerID,
         );
         if (messagesFromOtherPeers.length === 0) {
           continue;
         }
         // We take the most recent timestamp to make sure that
         // change_thread_read_status operation older
         // than it won't flip the status to read.
         const time = Math.max(
           messagesFromOtherPeers.map(message => message.time),
         );
         invariant(threadInfo.thick, 'Thread should be thick');
 
         // We aren't checking if the unread timestamp is lower than the time.
         // We're doing this because we want to flip the thread to unread after
         // any new message from a non-viewer.
         const updatedThreadInfo = threadInfo.minimallyEncoded
           ? {
               ...threadInfo,
               currentUser: {
                 ...threadInfo.currentUser,
                 unread: true,
               },
               timestamps: {
                 ...threadInfo.timestamps,
                 currentUser: {
                   ...threadInfo.timestamps.currentUser,
                   unread: time,
                 },
               },
             }
           : {
               ...threadInfo,
               currentUser: {
                 ...threadInfo.currentUser,
                 unread: true,
               },
               timestamps: {
                 ...threadInfo.timestamps,
                 currentUser: {
                   ...threadInfo.timestamps.currentUser,
                   unread: time,
                 },
               },
             };
 
         updateInfos.push({
           type: updateTypes.UPDATE_THREAD,
           id: uuid.v4(),
           time,
           threadInfo: updatedThreadInfo,
         });
       }
 
       dispatchWithMetadata(
         {
           type: processDMOpsActionType,
           payload: {
             rawMessageInfos,
             updateInfos,
             outboundP2PMessages,
             composableMessageID,
             notificationsCreationData,
           },
         },
         dispatchMetadata,
       );
     },
     [
       viewerID,
       utilities,
       dispatchWithMetadata,
       allPeerUserIDAndDeviceIDs,
       currentUserInfo,
       threadInfos,
       dispatch,
     ],
   );
 }
 
 function useProcessAndSendDMOperation(): (
   dmOperationSpecification: OutboundDMOperationSpecification,
 ) => Promise<void> {
   const processDMOps = useProcessDMOperation();
   const { getDMOpsSendingPromise } = usePeerToPeerCommunication();
 
   return React.useCallback(
     async (dmOperationSpecification: OutboundDMOperationSpecification) => {
       const { promise, dmOpID } = getDMOpsSendingPromise();
       await processDMOps(dmOperationSpecification, dmOpID);
       await promise;
     },
     [getDMOpsSendingPromise, processDMOps],
   );
 }
 
 function useSendComposableDMOperation(): (
   dmOperationSpecification: OutboundComposableDMOperationSpecification,
 ) => Promise<ProcessOutboundP2PMessagesResult> {
   const threadInfos = useSelector(state => state.threadStore.threadInfos);
   const { getDMOpsSendingPromise } = usePeerToPeerCommunication();
   const dispatchWithMetadata = useDispatchWithMetadata();
   const allPeerUserIDAndDeviceIDs = useSelector(getAllPeerUserIDAndDeviceIDs);
   const currentUserInfo = useSelector(state => state.currentUserInfo);
   const utilities = useSendDMOperationUtils();
   const { processOutboundMessages } = usePeerToPeerCommunication();
   const localMessageInfos = useSelector(state => state.messageStore.local);
 
   return React.useCallback(
     async (
       dmOperationSpecification: OutboundComposableDMOperationSpecification,
     ): Promise<ProcessOutboundP2PMessagesResult> => {
       const { promise, dmOpID } = getDMOpsSendingPromise();
 
       const { op, composableMessageID, recipients } = dmOperationSpecification;
 
       const localMessageInfo = localMessageInfos[composableMessageID];
       if (
         localMessageInfo?.outboundP2PMessageIDs &&
         localMessageInfo.outboundP2PMessageIDs.length > 0
       ) {
         processOutboundMessages(localMessageInfo.outboundP2PMessageIDs, dmOpID);
-        return promise;
+        try {
+          // This code should never throw.
+          return await promise;
+        } catch (e) {
+          invariant(
+            localMessageInfo.outboundP2PMessageIDs,
+            'outboundP2PMessageIDs should be defined',
+          );
+          return {
+            result: 'failure',
+            failedMessageIDs: localMessageInfo.outboundP2PMessageIDs,
+          };
+        }
       }
 
       const outboundP2PMessages = await createMessagesToPeersFromDMOp(
         op,
         recipients,
         allPeerUserIDAndDeviceIDs,
         currentUserInfo,
         threadInfos,
       );
 
       const notificationsCreationData = await dmOpSpecs[
         op.type
       ].notificationsCreationData?.(op, utilities);
 
       dispatchWithMetadata(
         {
           type: processDMOpsActionType,
           payload: {
             rawMessageInfos: [],
             updateInfos: [],
             outboundP2PMessages,
             composableMessageID,
             notificationsCreationData,
           },
         },
         {
           dmOpID,
         },
       );
 
-      return promise;
+      try {
+        // This code should never throw.
+        return await promise;
+      } catch (e) {
+        return {
+          result: 'failure',
+          failedMessageIDs: outboundP2PMessages.map(
+            message => message.messageID,
+          ),
+        };
+      }
     },
     [
       allPeerUserIDAndDeviceIDs,
       currentUserInfo,
       dispatchWithMetadata,
       getDMOpsSendingPromise,
       localMessageInfos,
       processOutboundMessages,
       threadInfos,
       utilities,
     ],
   );
 }
 
 export {
   useProcessDMOperation,
   useProcessAndSendDMOperation,
   useSendComposableDMOperation,
 };