diff --git a/src/components/Notification.tsx b/src/components/Notification.tsx
index 7a2edbee..3976044f 100644
--- a/src/components/Notification.tsx
+++ b/src/components/Notification.tsx
@@ -1,13 +1,13 @@
 // SPDX-License-Identifier: MIT
-// Copyright (c) 2020 The Pybricks Authors
+// Copyright (c) 2021 The Pybricks Authors
+
+// provides translation for notification text
 
 import { Replacements, useI18n } from '@shopify/react-i18n';
 import React from 'react';
 import { MessageId } from './notification-i18n';
 import en from './notification-i18n.en.json';
 
-// provides translation for notification text
-
 type OwnProps = {
     messageId: MessageId;
     replacements?: Replacements;
diff --git a/src/components/UnexpectedErrorNotification.tsx b/src/components/UnexpectedErrorNotification.tsx
new file mode 100644
index 00000000..8f9957ea
--- /dev/null
+++ b/src/components/UnexpectedErrorNotification.tsx
@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2021 The Pybricks Authors
+
+// Provides special notification contents for unexpected errors.
+
+import { AnchorButton, Button, ButtonGroup, Intent } from '@blueprintjs/core';
+import { useI18n } from '@shopify/react-i18n';
+import React from 'react';
+import { MessageId } from './notification-i18n';
+import en from './notification-i18n.en.json';
+
+type OwnProps = {
+    messageId: MessageId;
+    err: Error;
+};
+
+export default function UnexpectedErrorNotification(props: OwnProps): JSX.Element {
+    const [i18n] = useI18n({
+        id: 'notification',
+        translations: { en },
+        fallback: en,
+    });
+    const { messageId, err } = props;
+    return (
+        <>
+            <p>{i18n.translate(messageId, { errorMessage: err.message })}</p>
+            <div>
+                <ButtonGroup minimal={true} fill={true}>
+                    <Button
+                        intent={Intent.DANGER}
+                        icon="duplicate"
+                        onClick={() =>
+                            navigator.clipboard.writeText(
+                                `\`\`\`\n${err.stack || err.message}\n\`\`\``,
+                            )
+                        }
+                    >
+                        {i18n.translate(MessageId.CopyErrorMessage)}
+                    </Button>
+                    <AnchorButton
+                        intent={Intent.DANGER}
+                        icon="virus"
+                        href={`https://github.com/pybricks/support/issues?q=${encodeURIComponent(
+                            'is:issue',
+                        )}+${encodeURIComponent(err.message)}`}
+                        target="_blank"
+                    >
+                        {i18n.translate(MessageId.ReportBug)}
+                    </AnchorButton>
+                </ButtonGroup>
+            </div>
+        </>
+    );
+}
diff --git a/src/components/notification-i18n.en.json b/src/components/notification-i18n.en.json
index 90dc0233..d0ae6e09 100644
--- a/src/components/notification-i18n.en.json
+++ b/src/components/notification-i18n.en.json
@@ -1,9 +1,11 @@
 {
+    "copyErrorMessage": "Copy Error Message",
+    "reportBug": "Report Bug",
     "ble": {
         "gattPermission": "The web browser did not give permission to use Bluetooth Low Energy",
         "gattServiceNotFound": "Connected to hub but failed to get {serviceName} service. Try removing the \"{hubName}\" device in your OS Bluetooth settings, then try again.",
         "noWebBluetooth": "This web browser does not support Web Bluetooth or it is not enabled.",
-        "connectFailed": "Unexpected error while trying to connect. Check console log and report the error."
+        "unexpectedError": "Unexpected error while trying to connect: {errorMessage}"
     },
     "editor": {
         "programChanged": {
diff --git a/src/components/notification-i18n.ts b/src/components/notification-i18n.ts
index e5948e18..48414268 100644
--- a/src/components/notification-i18n.ts
+++ b/src/components/notification-i18n.ts
@@ -4,7 +4,9 @@
 // Notification translation keys.
 
 export enum MessageId {
-    BleConnectFailed = 'ble.connectFailed',
+    CopyErrorMessage = 'copyErrorMessage',
+    ReportBug = 'reportBug',
+    BleUnexpectedError = 'ble.unexpectedError',
     BleGattPermission = 'ble.gattPermission',
     BleGattServiceNotFound = 'ble.gattServiceNotFound',
     BleNoWebBluetooth = 'ble.noWebBluetooth',
diff --git a/src/sagas/notification.test.ts b/src/sagas/notification.test.ts
index 5ffd07f1..9b529eb9 100644
--- a/src/sagas/notification.test.ts
+++ b/src/sagas/notification.test.ts
@@ -27,7 +27,9 @@ test.each([
         reason: BleDeviceFailToConnectReasonType.Unknown,
         err: { name: 'test', message: 'unknown' },
     }),
-    bootloaderDidFailToConnect(BootloaderConnectionFailureReason.Unknown),
+    bootloaderDidFailToConnect(BootloaderConnectionFailureReason.Unknown, <Error>{
+        message: 'test',
+    }),
     bootloaderDidFailToConnect(BootloaderConnectionFailureReason.NoWebBluetooth),
     bootloaderDidFailToConnect(BootloaderConnectionFailureReason.GattServiceNotFound),
     storageChanged('test'),
diff --git a/src/sagas/notification.ts b/src/sagas/notification.ts
index d386583b..687e0e59 100644
--- a/src/sagas/notification.ts
+++ b/src/sagas/notification.ts
@@ -30,6 +30,7 @@ import { MpyActionType, MpyDidFailToCompileAction } from '../actions/mpy';
 import { NotificationActionType, NotificationAddAction } from '../actions/notification';
 import { ServiceWorkerActionType } from '../actions/service-worker';
 import Notification from '../components/Notification';
+import UnexpectedErrorNotification from '../components/UnexpectedErrorNotification';
 import { MessageId } from '../components/notification-i18n';
 import { appName } from '../settings/ui';
 
@@ -140,6 +141,17 @@ function* showSingleton(
     );
 }
 
+/** Shows a special notification for unexpected errors. */
+function* showUnexpectedError(messageId: MessageId, err: Error): Generator {
+    const { toaster } = (yield getContext('notification')) as NotificationContext;
+    toaster.show({
+        intent: mapIntent(Level.Error),
+        icon: mapIcon(Level.Error),
+        message: React.createElement(UnexpectedErrorNotification, { messageId, err }),
+        timeout: 0,
+    });
+}
+
 function* showBleDeviceDidFailToConnectError(
     action: BleDeviceDidFailToConnectAction,
 ): Generator {
@@ -165,7 +177,7 @@ function* showBleDeviceDidFailToConnectError(
             );
             break;
         case BleDeviceFailToConnectReasonType.Unknown:
-            yield* showSingleton(Level.Error, MessageId.BleConnectFailed);
+            yield* showUnexpectedError(MessageId.BleUnexpectedError, action.err);
             break;
     }
 }
@@ -191,7 +203,7 @@ function* showBootloaderDidFailToConnectError(
             );
             break;
         case BootloaderConnectionFailureReason.Unknown:
-            yield* showSingleton(Level.Error, MessageId.BleConnectFailed);
+            yield* showUnexpectedError(MessageId.BleUnexpectedError, action.err);
             break;
     }
 }