diff --git a/web/settings/relationship/add-users-list.css b/web/settings/relationship/add-users-list.css
index a9420e014..6cfe88d46 100644
--- a/web/settings/relationship/add-users-list.css
+++ b/web/settings/relationship/add-users-list.css
@@ -1,54 +1,63 @@
 .container {
   height: 625px;
   display: flex;
   flex-direction: column;
 }
 
 .userTagsContainer {
   display: flex;
   flex-wrap: wrap;
   gap: 6px;
   margin: 8px;
 }
 
 .userRowsContainer {
   overflow: auto;
   display: flex;
   flex-direction: column;
   flex: 1;
   margin-bottom: 8px;
 }
 
 .addUserButton {
   display: flex;
   flex-direction: row;
   justify-content: space-between;
   padding: 16px;
   color: var(--relationship-modal-color);
   font-size: var(--l-font-18);
   line-height: var(--line-height-display);
   background: transparent;
   border: none;
 }
 
 .addUserButtonUsername {
   white-space: nowrap;
   overflow: hidden;
   text-overflow: ellipsis;
 }
 
 .buttons {
   display: flex;
   justify-content: space-between;
 }
 
 .confirmButtonContainer {
   display: flex;
   flex-direction: column;
   align-items: center;
 }
 
 .hidden {
   visibility: hidden;
   height: 0;
 }
+
+.error {
+  padding-bottom: 8px;
+  font-size: var(--s-font-14);
+  line-height: var(--line-height-display);
+  color: var(--error);
+  padding-left: 6px;
+  font-style: italic;
+}
diff --git a/web/settings/relationship/add-users-list.react.js b/web/settings/relationship/add-users-list.react.js
index 5176a8cd1..5d12513c4 100644
--- a/web/settings/relationship/add-users-list.react.js
+++ b/web/settings/relationship/add-users-list.react.js
@@ -1,237 +1,250 @@
 // @flow
 
 import * as React from 'react';
 
 import {
   updateRelationships,
   updateRelationshipsActionTypes,
 } from 'lib/actions/relationship-actions.js';
 import { searchUsers } from 'lib/actions/user-actions.js';
 import { createLoadingStatusSelector } from 'lib/selectors/loading-selectors.js';
 import { userStoreSearchIndex as userStoreSearchIndexSelector } from 'lib/selectors/user-selectors.js';
 import type {
   UserRelationshipStatus,
   RelationshipAction,
 } from 'lib/types/relationship-types.js';
 import type { GlobalAccountUserInfo } from 'lib/types/user-types.js';
 import {
   useDispatchActionPromise,
   useServerCall,
 } from 'lib/utils/action-utils.js';
 
 import Button from '../../components/button.react.js';
 import type { ButtonVariant } from '../../components/button.react.js';
 import Label from '../../components/label.react.js';
 import LoadingIndicator from '../../loading-indicator.react.js';
 import { useSelector } from '../../redux/redux-utils.js';
 import AddUsersListItem from './add-users-list-item.react.js';
 import css from './add-users-list.css';
 
 const loadingStatusSelector = createLoadingStatusSelector(
   updateRelationshipsActionTypes,
 );
 
 type Props = {
   +searchText: string,
   +excludedStatuses?: $ReadOnlySet<UserRelationshipStatus>,
   +closeModal: () => void,
   +confirmButtonContent: React.Node,
   +confirmButtonVariant: ButtonVariant,
   +relationshipAction: RelationshipAction,
 };
 
 function AddUsersList(props: Props): React.Node {
   const {
     searchText,
     excludedStatuses = new Set(),
     closeModal,
     confirmButtonContent,
     confirmButtonVariant,
     relationshipAction,
   } = props;
 
   const userStoreSearchIndex = useSelector(userStoreSearchIndexSelector);
   const [userStoreSearchResults, setUserStoreSearchResults] = React.useState<
     $ReadOnlySet<string>,
   >(new Set(userStoreSearchIndex.getSearchResults(searchText)));
   React.useEffect(() => {
     setUserStoreSearchResults(
       new Set(userStoreSearchIndex.getSearchResults(searchText)),
     );
   }, [searchText, userStoreSearchIndex]);
 
   const [serverSearchResults, setServerSearchResults] = React.useState<
     $ReadOnlyArray<GlobalAccountUserInfo>,
   >([]);
   const callSearchUsers = useServerCall(searchUsers);
   React.useEffect(() => {
     (async () => {
       if (searchText.length === 0) {
         setServerSearchResults([]);
       } else {
         const { userInfos } = await callSearchUsers(searchText);
         setServerSearchResults(userInfos);
       }
     })();
   }, [callSearchUsers, searchText]);
 
   const searchTextPresent = searchText.length > 0;
   const userInfos = useSelector(state => state.userStore.userInfos);
   const mergedUserInfos = React.useMemo(() => {
     const mergedInfos = {};
 
     for (const userInfo of serverSearchResults) {
       mergedInfos[userInfo.id] = userInfo;
     }
 
     const userStoreUserIDs = searchTextPresent
       ? userStoreSearchResults
       : Object.keys(userInfos);
     for (const id of userStoreUserIDs) {
       const { username, relationshipStatus } = userInfos[id];
       if (username) {
         mergedInfos[id] = { id, username, relationshipStatus };
       }
     }
 
     return mergedInfos;
   }, [
     searchTextPresent,
     serverSearchResults,
     userInfos,
     userStoreSearchResults,
   ]);
 
   const sortedUsers = React.useMemo(
     () =>
       Object.keys(mergedUserInfos)
         .map(userID => mergedUserInfos[userID])
         .filter(user => !excludedStatuses.has(user.relationshipStatus))
         .sort((user1, user2) => user1.username.localeCompare(user2.username)),
     [excludedStatuses, mergedUserInfos],
   );
 
   const [pendingUsersToAdd, setPendingUsersToAdd] = React.useState<
     $ReadOnlyArray<GlobalAccountUserInfo>,
   >([]);
   const selectUser = React.useCallback(
     (userID: string) => {
       setPendingUsersToAdd(pendingUsers => {
         const username = mergedUserInfos[userID]?.username;
         if (!username || pendingUsers.some(user => user.id === userID)) {
           return pendingUsers;
         }
 
         const newPendingUser = {
           id: userID,
           username,
         };
         let targetIndex = 0;
         while (
           targetIndex < pendingUsers.length &&
           newPendingUser.username.localeCompare(
             pendingUsers[targetIndex].username,
           ) > 0
         ) {
           targetIndex++;
         }
         return [
           ...pendingUsers.slice(0, targetIndex),
           newPendingUser,
           ...pendingUsers.slice(targetIndex),
         ];
       });
     },
     [mergedUserInfos],
   );
   const deselectUser = React.useCallback(
     (userID: string) =>
       setPendingUsersToAdd(pendingUsers =>
         pendingUsers.filter(userInfo => userInfo.id !== userID),
       ),
     [],
   );
   const pendingUserIDs = React.useMemo(
     () => new Set(pendingUsersToAdd.map(userInfo => userInfo.id)),
     [pendingUsersToAdd],
   );
 
   const userTags = React.useMemo(() => {
     if (pendingUsersToAdd.length === 0) {
       return null;
     }
     const tags = pendingUsersToAdd.map(userInfo => (
       <Label key={userInfo.id} onClose={() => deselectUser(userInfo.id)}>
         {userInfo.username}
       </Label>
     ));
     return <div className={css.userTagsContainer}>{tags}</div>;
   }, [deselectUser, pendingUsersToAdd]);
 
   const filteredUsers = React.useMemo(
     () => sortedUsers.filter(userInfo => !pendingUserIDs.has(userInfo.id)),
     [pendingUserIDs, sortedUsers],
   );
 
   const userRows = React.useMemo(
     () =>
       filteredUsers.map(userInfo => (
         <AddUsersListItem
           userInfo={userInfo}
           key={userInfo.id}
           selectUser={selectUser}
         />
       )),
     [filteredUsers, selectUser],
   );
 
+  const [errorMessage, setErrorMessage] = React.useState('');
   const callUpdateRelationships = useServerCall(updateRelationships);
   const dispatchActionPromise = useDispatchActionPromise();
   const updateRelationshipsPromiseCreator = React.useCallback(async () => {
-    const result = await callUpdateRelationships({
-      action: relationshipAction,
-      userIDs: Array.from(pendingUserIDs),
-    });
-    closeModal();
-    return result;
+    try {
+      setErrorMessage('');
+      const result = await callUpdateRelationships({
+        action: relationshipAction,
+        userIDs: Array.from(pendingUserIDs),
+      });
+      closeModal();
+      return result;
+    } catch (e) {
+      setErrorMessage('unknown error');
+      throw e;
+    }
   }, [callUpdateRelationships, closeModal, pendingUserIDs, relationshipAction]);
   const confirmSelection = React.useCallback(
     () =>
       dispatchActionPromise(
         updateRelationshipsActionTypes,
         updateRelationshipsPromiseCreator(),
       ),
     [dispatchActionPromise, updateRelationshipsPromiseCreator],
   );
   const loadingStatus = useSelector(loadingStatusSelector);
   let buttonContent = confirmButtonContent;
   if (loadingStatus === 'loading') {
     buttonContent = (
       <>
         <div className={css.hidden}>{confirmButtonContent}</div>
         <LoadingIndicator status="loading" />
       </>
     );
   }
 
+  let errors;
+  if (errorMessage) {
+    errors = <div className={css.error}>{errorMessage}</div>;
+  }
+
   return (
     <div className={css.container}>
       {userTags}
       <div className={css.userRowsContainer}>{userRows}</div>
+      {errors}
       <div className={css.buttons}>
         <Button variant="secondary" onClick={closeModal}>
           Cancel
         </Button>
         <Button
           onClick={confirmSelection}
           disabled={pendingUserIDs.size === 0 || loadingStatus === 'loading'}
           variant={confirmButtonVariant}
         >
           <div className={css.confirmButtonContainer}>{buttonContent}</div>
         </Button>
       </div>
     </div>
   );
 }
 
 export default AddUsersList;