diff --git a/src/UnknownDeviceErrorHandler.js b/src/UnknownDeviceErrorHandler.js
deleted file mode 100644
index e7d77b3b66..0000000000
--- a/src/UnknownDeviceErrorHandler.js
+++ /dev/null
@@ -1,51 +0,0 @@
-/*
-Copyright 2017 Vector Creations Ltd
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-import dis from './dispatcher';
-import sdk from './index';
-import Modal from './Modal';
-
-let isDialogOpen = false;
-
-const onAction = function(payload) {
-    if (payload.action === 'unknown_device_error' && !isDialogOpen) {
-        const UnknownDeviceDialog = sdk.getComponent('dialogs.UnknownDeviceDialog');
-        isDialogOpen = true;
-        Modal.createTrackedDialog('Unknown Device Error', '', UnknownDeviceDialog, {
-            devices: payload.err.devices,
-            room: payload.room,
-            onFinished: (r) => {
-                isDialogOpen = false;
-                // XXX: temporary logging to try to diagnose
-                // https://github.com/vector-im/riot-web/issues/3148
-                console.log('UnknownDeviceDialog closed with '+r);
-            },
-        }, 'mx_Dialog_unknownDevice');
-    }
-};
-
-let ref = null;
-
-export function startListening() {
-    ref = dis.register(onAction);
-}
-
-export function stopListening() {
-    if (ref) {
-        dis.unregister(ref);
-        ref = null;
-    }
-}
diff --git a/src/components/structures/MatrixChat.js b/src/components/structures/MatrixChat.js
index e8ca8e82fc..72497f527f 100644
--- a/src/components/structures/MatrixChat.js
+++ b/src/components/structures/MatrixChat.js
@@ -41,7 +41,6 @@ require('../../stores/LifecycleStore');
 import PageTypes from '../../PageTypes';
 
 import createRoom from "../../createRoom";
-import * as UDEHandler from '../../UnknownDeviceErrorHandler';
 import KeyRequestHandler from '../../KeyRequestHandler';
 import { _t, getCurrentLanguage } from '../../languageHandler';
 
@@ -280,7 +279,6 @@ module.exports = React.createClass({
 
     componentDidMount: function() {
         this.dispatcherRef = dis.register(this.onAction);
-        UDEHandler.startListening();
 
         this.focusComposer = false;
 
@@ -346,7 +344,6 @@ module.exports = React.createClass({
     componentWillUnmount: function() {
         Lifecycle.stopMatrixClient();
         dis.unregister(this.dispatcherRef);
-        UDEHandler.stopListening();
         window.removeEventListener("focus", this.onFocus);
         window.removeEventListener('resize', this.handleResize);
     },
diff --git a/src/components/structures/RoomStatusBar.js b/src/components/structures/RoomStatusBar.js
index cad55351d1..c37cc7deef 100644
--- a/src/components/structures/RoomStatusBar.js
+++ b/src/components/structures/RoomStatusBar.js
@@ -1,5 +1,6 @@
 /*
 Copyright 2015, 2016 OpenMarket Ltd
+Copyright 2017 New Vector Ltd
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -16,16 +17,26 @@ limitations under the License.
 
 import React from 'react';
 import { _t, _tJsx } from '../../languageHandler';
+import Matrix from 'matrix-js-sdk';
 import sdk from '../../index';
 import WhoIsTyping from '../../WhoIsTyping';
 import MatrixClientPeg from '../../MatrixClientPeg';
 import MemberAvatar from '../views/avatars/MemberAvatar';
+import Resend from '../../Resend';
+import Modal from '../../Modal';
 
 const HIDE_DEBOUNCE_MS = 10000;
 const STATUS_BAR_HIDDEN = 0;
 const STATUS_BAR_EXPANDED = 1;
 const STATUS_BAR_EXPANDED_LARGE = 2;
 
+function getUnsentMessages(room) {
+    if (!room) { return []; }
+    return room.getPendingEvents().filter(function(ev) {
+        return ev.status === Matrix.EventStatus.NOT_SENT;
+    });
+};
+
 module.exports = React.createClass({
     displayName: 'RoomStatusBar',
 
@@ -36,9 +47,6 @@ module.exports = React.createClass({
         // the number of messages which have arrived since we've been scrolled up
         numUnreadMessages: React.PropTypes.number,
 
-        // string to display when there are messages in the room which had errors on send
-        unsentMessageError: React.PropTypes.string,
-
         // this is true if we are fully scrolled-down, and are looking at
         // the end of the live timeline.
         atEndOfLiveTimeline: React.PropTypes.bool,
@@ -99,12 +107,14 @@ module.exports = React.createClass({
         return {
             syncState: MatrixClientPeg.get().getSyncState(),
             usersTyping: WhoIsTyping.usersTypingApartFromMe(this.props.room),
+            unsentMessages: [],
         };
     },
 
     componentWillMount: function() {
         MatrixClientPeg.get().on("sync", this.onSyncStateChange);
         MatrixClientPeg.get().on("RoomMember.typing", this.onRoomMemberTyping);
+        MatrixClientPeg.get().on("Room.localEchoUpdated", this.onRoomLocalEchoUpdated);
 
         this._checkSize();
     },
@@ -119,6 +129,7 @@ module.exports = React.createClass({
         if (client) {
             client.removeListener("sync", this.onSyncStateChange);
             client.removeListener("RoomMember.typing", this.onRoomMemberTyping);
+            client.removeListener("Room.localEchoUpdated", this.onRoomLocalEchoUpdated);
         }
     },
 
@@ -137,6 +148,57 @@ module.exports = React.createClass({
         });
     },
 
+    _onResendAllClick: function() {
+        Resend.resendUnsentEvents(this.props.room);
+    },
+
+    _onCancelAllClick: function() {
+        Resend.cancelUnsentEvents(this.props.room);
+    },
+
+    _onShowDevicesClick: function() {
+        this._getUnknownDevices().then((unknownDevices) => {
+            const UnknownDeviceDialog = sdk.getComponent('dialogs.UnknownDeviceDialog');
+            Modal.createTrackedDialog('Unknown Device Dialog', '', UnknownDeviceDialog, {
+                room: this.props.room,
+                devices: unknownDevices,
+            }, 'mx_Dialog_unknownDevice');
+        });
+    },
+
+    _getUnknownDevices: function() {
+        const roomMembers = this.props.room.getJoinedMembers().map((m) => {
+            return m.userId;
+        });
+        return MatrixClientPeg.get().downloadKeys(roomMembers, false).then((devices) => {
+            if (this._unmounted) return;
+
+            const unknownDevices = {};
+            // This is all devices in this room, so find the unknown ones.
+            Object.keys(devices).forEach((userId) => {
+                Object.keys(devices[userId]).map((deviceId) => {
+                    const device = devices[userId][deviceId];
+
+                    if (device.isUnverified() && !device.isKnown()) {
+                        if (unknownDevices[userId] === undefined) {
+                            unknownDevices[userId] = {};
+                        }
+                        unknownDevices[userId][deviceId] = device;
+                    }
+                });
+            });
+            return unknownDevices;
+        });
+    },
+
+    onRoomLocalEchoUpdated: function(event, room, oldEventId, oldStatus) {
+        if (room.roomId !== this.props.room.roomId) return;
+
+        this.setState({
+            unsentMessages: getUnsentMessages(this.props.room),
+        });
+    },
+
     // Check whether current size is greater than 0, if yes call props.onVisible
     _checkSize: function() {
         if (this.props.onVisible && this._getSize()) {
@@ -156,7 +218,7 @@ module.exports = React.createClass({
             this.props.sentMessageAndIsAlone
         ) {
             return STATUS_BAR_EXPANDED;
-        } else if (this.props.unsentMessageError) {
+        } else if (this.state.unsentMessages.length > 0) {
             return STATUS_BAR_EXPANDED_LARGE;
         }
         return STATUS_BAR_HIDDEN;
@@ -242,6 +304,60 @@ module.exports = React.createClass({
         return avatars;
     },
 
+    _getUnsentMessageContent: function(room) {
+        const unsentMessages = this.state.unsentMessages;
+        if (!unsentMessages.length) return null;
+
+        let title;
+        let content;
+
+        const hasUDE = unsentMessages.some((m) => {
+            return m.error && m.error.name === "UnknownDeviceError";
+        });
+
+        if (hasUDE) {
+            title = _t("Message not sent due to unknown devices being present");
+            content = _tJsx(
+                "<a>Show devices</a> or <a>cancel all</a>.",
+                [/<a>(.*?)<\/a>/, /<a>(.*?)<\/a>/],
+                [
+                    (sub) => <a className="mx_RoomStatusBar_resend_link" key="resend" onClick={this._onShowDevicesClick}>{ sub }</a>,
+                    (sub) => <a className="mx_RoomStatusBar_resend_link" key="cancel" onClick={this._onCancelAllClick}>{ sub }</a>,
+                ],
+            );
+        } else {
+            if (
+                unsentMessages.length === 1 &&
+                unsentMessages[0].error &&
+                unsentMessages[0].error.data &&
+                unsentMessages[0].error.data.error
+            ) {
+                title = unsentMessages[0].error.data.error;
+            } else {
+                title = _t("Some of your messages have not been sent.");
+            }
+            content = _tJsx(
+                "<a>Resend all</a> or <a>cancel all</a> now. "+
+                "You can also select individual messages to resend or cancel.",
+                [/<a>(.*?)<\/a>/, /<a>(.*?)<\/a>/],
+                [
+                    (sub) => <a className="mx_RoomStatusBar_resend_link" key="resend" onClick={this._onResendAllClick}>{ sub }</a>,
+                    (sub) => <a className="mx_RoomStatusBar_resend_link" key="cancel" onClick={this._onCancelAllClick}>{ sub }</a>,
+                ],
+            );
+        }
+
+        return <div className="mx_RoomStatusBar_connectionLostBar">
+            <img src="img/warning.svg" width="24" height="23" title={_t("Warning")} alt={_t("Warning")} />
+            <div className="mx_RoomStatusBar_connectionLostBar_title">
+                { title }
+            </div>
+            <div className="mx_RoomStatusBar_connectionLostBar_desc">
+                { content }
+            </div>
+        </div>;
+    },
+
     // return suitable content for the main (text) part of the status bar.
     _getContent: function() {
         const EmojiText = sdk.getComponent('elements.EmojiText');
@@ -264,24 +380,8 @@ module.exports = React.createClass({
             );
         }
 
-        if (this.props.unsentMessageError) {
-            return (
-                <div className="mx_RoomStatusBar_connectionLostBar">
-                    <img src="img/warning.svg" width="24" height="23" title="/!\ " alt="/!\ " />
-                    <div className="mx_RoomStatusBar_connectionLostBar_title">
-                        { this.props.unsentMessageError }
-                    </div>
-                    <div className="mx_RoomStatusBar_connectionLostBar_desc">
-                    { _tJsx("<a>Resend all</a> or <a>cancel all</a> now. You can also select individual messages to resend or cancel.",
-                        [/<a>(.*?)<\/a>/, /<a>(.*?)<\/a>/],
-                        [
-                            (sub) => <a className="mx_RoomStatusBar_resend_link" key="resend" onClick={this.props.onResendAllClick}>{ sub }</a>,
-                            (sub) => <a className="mx_RoomStatusBar_resend_link" key="cancel" onClick={this.props.onCancelAllClick}>{ sub }</a>,
-                        ],
-                    ) }
-                    </div>
-                </div>
-            );
+        if (this.state.unsentMessages.length > 0) {
+            return this._getUnsentMessageContent();
         }
 
         // unread count trumps who is typing since the unread count is only
diff --git a/src/components/structures/RoomView.js b/src/components/structures/RoomView.js
index 409b95947f..0f4531ecef 100644
--- a/src/components/structures/RoomView.js
+++ b/src/components/structures/RoomView.js
@@ -26,7 +26,6 @@ const React = require("react");
 const ReactDOM = require("react-dom");
 import Promise from 'bluebird';
 const classNames = require("classnames");
-const Matrix = require("matrix-js-sdk");
 import { _t } from '../../languageHandler';
 
 const UserSettingsStore = require('../../UserSettingsStore');
@@ -35,7 +34,6 @@ const ContentMessages = require("../../ContentMessages");
 const Modal = require("../../Modal");
 const sdk = require('../../index');
 const CallHandler = require('../../CallHandler');
-const Resend = require("../../Resend");
 const dis = require("../../dispatcher");
 const Tinter = require("../../Tinter");
 const rate_limited_func = require('../../ratelimitedfunc');
@@ -110,7 +108,6 @@ module.exports = React.createClass({
             draggingFile: false,
             searching: false,
             searchResults: null,
-            unsentMessageError: '',
             callState: null,
             guestsCanJoin: false,
             canPeek: false,
@@ -204,7 +201,6 @@ module.exports = React.createClass({
         if (initial) {
             newState.room = MatrixClientPeg.get().getRoom(newState.roomId);
             if (newState.room) {
-                newState.unsentMessageError = this._getUnsentMessageError(newState.room);
                 newState.showApps = this._shouldShowApps(newState.room);
                 this._onRoomLoaded(newState.room);
             }
@@ -470,11 +466,6 @@ module.exports = React.createClass({
             case 'message_send_failed':
             case 'message_sent':
                 this._checkIfAlone(this.state.room);
-                // no break; to intentionally fall through
-            case 'message_send_cancelled':
-                this.setState({
-                    unsentMessageError: this._getUnsentMessageError(this.state.room),
-                });
                 break;
             case 'notifier_enabled':
             case 'upload_failed':
@@ -754,35 +745,6 @@ module.exports = React.createClass({
         this.setState({isAlone: joinedMembers.length === 1});
     },
 
-    _getUnsentMessageError: function(room) {
-        const unsentMessages = this._getUnsentMessages(room);
-        if (!unsentMessages.length) return "";
-
-        if (
-            unsentMessages.length === 1 &&
-            unsentMessages[0].error &&
-            unsentMessages[0].error.data &&
-            unsentMessages[0].error.data.error &&
-            unsentMessages[0].error.name !== "UnknownDeviceError"
-        ) {
-            return unsentMessages[0].error.data.error;
-        }
-
-        for (const event of unsentMessages) {
-            if (!event.error || event.error.name !== "UnknownDeviceError") {
-                return _t("Some of your messages have not been sent.");
-            }
-        }
-        return _t("Message not sent due to unknown devices being present");
-    },
-
-    _getUnsentMessages: function(room) {
-        if (!room) { return []; }
-        return room.getPendingEvents().filter(function(ev) {
-            return ev.status === Matrix.EventStatus.NOT_SENT;
-        });
-    },
-
     _updateConfCallNotification: function() {
         const room = this.state.room;
         if (!room || !this.props.ConferenceHandler) {
@@ -827,14 +789,6 @@ module.exports = React.createClass({
         }
     },
 
-    onResendAllClick: function() {
-        Resend.resendUnsentEvents(this.state.room);
-    },
-
-    onCancelAllClick: function() {
-        Resend.cancelUnsentEvents(this.state.room);
-    },
-
     onInviteButtonClick: function() {
         // call AddressPickerDialog
         dis.dispatch({
@@ -1614,12 +1568,9 @@ module.exports = React.createClass({
             statusBar = <RoomStatusBar
                 room={this.state.room}
                 numUnreadMessages={this.state.numUnreadMessages}
-                unsentMessageError={this.state.unsentMessageError}
                 atEndOfLiveTimeline={this.state.atEndOfLiveTimeline}
                 sentMessageAndIsAlone={this.state.isAlone}
                 hasActiveCall={inCall}
-                onResendAllClick={this.onResendAllClick}
-                onCancelAllClick={this.onCancelAllClick}
                 onInviteClick={this.onInviteButtonClick}
                 onStopWarningClick={this.onStopAloneWarningClick}
                 onScrollToBottomClick={this.jumpToLiveTimeline}
diff --git a/src/components/views/dialogs/UnknownDeviceDialog.js b/src/components/views/dialogs/UnknownDeviceDialog.js
index ee8f307f76..5bcbce78fe 100644
--- a/src/components/views/dialogs/UnknownDeviceDialog.js
+++ b/src/components/views/dialogs/UnknownDeviceDialog.js
@@ -1,5 +1,6 @@
 /*
 Copyright 2017 Vector Creations Ltd
+Copyright 2017 New Vector Ltd
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -97,18 +98,19 @@ export default React.createClass({
         onFinished: React.PropTypes.func.isRequired,
     },
 
-    componentDidMount: function() {
-        // Given we've now shown the user the unknown device, it is no longer
-        // unknown to them. Therefore mark it as 'known'.
+    _onSendAnywayClicked: function() {
+        // Mark the devices as known so messages get encrypted to them
         Object.keys(this.props.devices).forEach((userId) => {
             Object.keys(this.props.devices[userId]).map((deviceId) => {
                 MatrixClientPeg.get().setDeviceKnown(userId, deviceId, true);
             });
         });
+        this.props.onFinished();
+        Resend.resendUnsentEvents(this.props.room);
+    },
 
-        // XXX: temporary logging to try to diagnose
-        // https://github.com/vector-im/riot-web/issues/3148
-        console.log('Opening UnknownDeviceDialog');
+    _onDismissClicked: function() {
+        this.props.onFinished();
     },
 
     render: function() {
@@ -139,12 +141,7 @@ export default React.createClass({
         const BaseDialog = sdk.getComponent('views.dialogs.BaseDialog');
         return (
             <BaseDialog className='mx_UnknownDeviceDialog'
-                onFinished={() => {
-                            // XXX: temporary logging to try to diagnose
-                            // https://github.com/vector-im/riot-web/issues/3148
-                            console.log("UnknownDeviceDialog closed by escape");
-                            this.props.onFinished();
-                }}
+                onFinished={this.props.onFinished}
                 title={_t('Room contains unknown devices')}
             >
                 <GeminiScrollbar autoshow={false} className="mx_Dialog_content">
@@ -157,21 +154,13 @@ export default React.createClass({
                     <UnknownDeviceList devices={this.props.devices} />
                 </GeminiScrollbar>
                 <div className="mx_Dialog_buttons">
-                    <button className="mx_Dialog_primary" autoFocus={true}
-                            onClick={() => {
-                                this.props.onFinished();
-                                Resend.resendUnsentEvents(this.props.room);
-                            }}>
+                    <button onClick={this._onSendAnywayClicked}>
                         { _t("Send anyway") }
                     </button>
                     <button className="mx_Dialog_primary" autoFocus={true}
-                            onClick={() => {
-                                // XXX: temporary logging to try to diagnose
-                                // https://github.com/vector-im/riot-web/issues/3148
-                                console.log("UnknownDeviceDialog closed by OK");
-                                this.props.onFinished();
-                            }}>
-                        OK
+                        onClick={this._onDismissClicked}
+                    >
+                        {_t("Dismiss")}
                     </button>
                 </div>
             </BaseDialog>
diff --git a/src/i18n/strings/en_EN.json b/src/i18n/strings/en_EN.json
index 4052d098c1..b83600ffb6 100644
--- a/src/i18n/strings/en_EN.json
+++ b/src/i18n/strings/en_EN.json
@@ -727,17 +727,19 @@
     "To join an existing community you'll have to know its community identifier; this will look something like <i>+example:matrix.org</i>.": "To join an existing community you'll have to know its community identifier; this will look something like <i>+example:matrix.org</i>.",
     "You have no visible notifications": "You have no visible notifications",
     "Scroll to bottom of page": "Scroll to bottom of page",
+    "Message not sent due to unknown devices being present": "Message not sent due to unknown devices being present",
+    "<a>Show devices</a> or <a>cancel all</a>.": "<a>Show devices</a> or <a>cancel all</a>.",
+    "Some of your messages have not been sent.": "Some of your messages have not been sent.",
+    "<a>Resend all</a> or <a>cancel all</a> now. You can also select individual messages to resend or cancel.": "<a>Resend all</a> or <a>cancel all</a> now. You can also select individual messages to resend or cancel.",
+    "Warning": "Warning",
     "Connectivity to the server has been lost.": "Connectivity to the server has been lost.",
     "Sent messages will be stored until your connection has returned.": "Sent messages will be stored until your connection has returned.",
-    "<a>Resend all</a> or <a>cancel all</a> now. You can also select individual messages to resend or cancel.": "<a>Resend all</a> or <a>cancel all</a> now. You can also select individual messages to resend or cancel.",
     "%(count)s new messages|other": "%(count)s new messages",
     "%(count)s new messages|one": "%(count)s new message",
     "Active call": "Active call",
     "There's no one else here! Would you like to <a>invite others</a> or <a>stop warning about the empty room</a>?": "There's no one else here! Would you like to <a>invite others</a> or <a>stop warning about the empty room</a>?",
     "You seem to be uploading files, are you sure you want to quit?": "You seem to be uploading files, are you sure you want to quit?",
     "You seem to be in a call, are you sure you want to quit?": "You seem to be in a call, are you sure you want to quit?",
-    "Some of your messages have not been sent.": "Some of your messages have not been sent.",
-    "Message not sent due to unknown devices being present": "Message not sent due to unknown devices being present",
     "Failed to upload file": "Failed to upload file",
     "Server may be unavailable, overloaded, or the file too big": "Server may be unavailable, overloaded, or the file too big",
     "Search failed": "Search failed",