diff --git a/src/Modal.js b/src/Modal.js
index b6cc46ed45..7be37da92e 100644
--- a/src/Modal.js
+++ b/src/Modal.js
@@ -43,7 +43,13 @@ const AsyncWrapper = React.createClass({
 
     componentWillMount: function() {
         this._unmounted = false;
+        // XXX: temporary logging to try to diagnose
+        // https://github.com/vector-im/riot-web/issues/3148
+        console.log('Starting load of AsyncWrapper for modal');
         this.props.loader((e) => {
+            // XXX: temporary logging to try to diagnose
+            // https://github.com/vector-im/riot-web/issues/3148
+            console.log('AsyncWrapper load completed with '+e.displayName);
             if (this._unmounted) {
                 return;
             }
diff --git a/src/Resend.js b/src/Resend.js
index ad0f58eb9b..e2f0c5a1ee 100644
--- a/src/Resend.js
+++ b/src/Resend.js
@@ -29,11 +29,19 @@ module.exports = {
                 event: event
             });
         }, function(err) {
+            // XXX: temporary logging to try to diagnose
+            // https://github.com/vector-im/riot-web/issues/3148
+            console.log('Resend got send failure: ' + err.name + '('+err+')');
             if (err.name === "UnknownDeviceError") {
                 var UnknownDeviceDialog = sdk.getComponent("dialogs.UnknownDeviceDialog");
                 Modal.createDialog(UnknownDeviceDialog, {
                     devices: err.devices,
                     room: MatrixClientPeg.get().getRoom(event.getRoomId()),
+                    onFinished: (r) => {
+                        // 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");
             }
 
diff --git a/src/components/views/dialogs/UnknownDeviceDialog.js b/src/components/views/dialogs/UnknownDeviceDialog.js
index 409852a2cc..3bebb8fdda 100644
--- a/src/components/views/dialogs/UnknownDeviceDialog.js
+++ b/src/components/views/dialogs/UnknownDeviceDialog.js
@@ -103,6 +103,10 @@ export default React.createClass({
                 MatrixClientPeg.get().setDeviceKnown(userId, deviceId, true);
             });
         });
+
+        // XXX: temporary logging to try to diagnose
+        // https://github.com/vector-im/riot-web/issues/3148
+        console.log('Opening UnknownDeviceDialog');
     },
 
     render: function() {
@@ -137,7 +141,12 @@ export default React.createClass({
         const BaseDialog = sdk.getComponent('views.dialogs.BaseDialog');
         return (
             <BaseDialog className='mx_UnknownDeviceDialog'
-                onFinished={this.props.onFinished}
+                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();
+                }}
                 title='Room contains unknown devices'
             >
                 <GeminiScrollbar autoshow={false} className="mx_Dialog_content">
@@ -152,7 +161,12 @@ export default React.createClass({
                 </GeminiScrollbar>
                 <div className="mx_Dialog_buttons">
                     <button className="mx_Dialog_primary" autoFocus={ true }
-                            onClick={ this.props.onFinished } >
+                            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
                     </button>
                 </div>
diff --git a/src/components/views/rooms/MessageComposerInputOld.js b/src/components/views/rooms/MessageComposerInputOld.js
index b91e5c4391..63821b7d96 100644
--- a/src/components/views/rooms/MessageComposerInputOld.js
+++ b/src/components/views/rooms/MessageComposerInputOld.js
@@ -30,11 +30,19 @@ var TYPING_SERVER_TIMEOUT = 30000;
 var MARKDOWN_ENABLED = true;
 
 export function onSendMessageFailed(err, room) {
+    // XXX: temporary logging to try to diagnose
+    // https://github.com/vector-im/riot-web/issues/3148
+    console.log('MessageComposer got send failure: ' + err.name + '('+err+')');
     if (err.name === "UnknownDeviceError") {
         const UnknownDeviceDialog = sdk.getComponent("dialogs.UnknownDeviceDialog");
         Modal.createDialog(UnknownDeviceDialog, {
             devices: err.devices,
             room: room,
+            onFinished: (r) => {
+                // 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");
     }
     dis.dispatch({