From cd32ef60da4b6fad04940a207af4f3317e314f1c Mon Sep 17 00:00:00 2001
From: Charles Garwood <cgarwood@gmail.com>
Date: Wed, 30 Sep 2020 17:09:48 -0400
Subject: [PATCH] Show error if no OZW instances are detected (#7176)

---
 .../ozw/ozw-config-dashboard.ts                  | 16 +++++++++++++++-
 src/translations/en.json                         |  3 ++-
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/src/panels/config/integrations/integration-panels/ozw/ozw-config-dashboard.ts b/src/panels/config/integrations/integration-panels/ozw/ozw-config-dashboard.ts
index 478ede0f8e..ee05890a37 100644
--- a/src/panels/config/integrations/integration-panels/ozw/ozw-config-dashboard.ts
+++ b/src/panels/config/integrations/integration-panels/ozw/ozw-config-dashboard.ts
@@ -28,6 +28,8 @@ import type { PageNavigation } from "../../../../../layouts/hass-tabs-subpage";
 import { haStyle } from "../../../../../resources/styles";
 import type { HomeAssistant, Route } from "../../../../../types";
 import "../../../ha-config-section";
+import "../../../../../layouts/hass-error-screen";
+import "../../../../../layouts/hass-loading-screen";
 
 export const ozwTabs: PageNavigation[] = [];
 
@@ -43,13 +45,25 @@ class OZWConfigDashboard extends LitElement {
 
   @property() public configEntryId?: string;
 
-  @internalProperty() private _instances: OZWInstance[] = [];
+  @internalProperty() private _instances?: OZWInstance[];
 
   protected firstUpdated() {
     this._fetchData();
   }
 
   protected render(): TemplateResult {
+    if (!this._instances) {
+      return html`<hass-loading-screen></hass-loading-screen>`;
+    }
+
+    if (this._instances.length === 0) {
+      return html`<hass-error-screen
+        .error="${this.hass.localize(
+          "ui.panel.config.ozw.select_instance.none_found"
+        )}"
+      ></hass-error-screen>`;
+    }
+
     return html`
       <hass-tabs-subpage
         .hass=${this.hass}
diff --git a/src/translations/en.json b/src/translations/en.json
index 11b2e3fb1c..690c71de3e 100755
--- a/src/translations/en.json
+++ b/src/translations/en.json
@@ -1894,7 +1894,8 @@
           },
           "select_instance": {
             "header": "Select an OpenZWave Instance",
-            "introduction": "You have more than one OpenZWave instance running. Which instance would you like to manage?"
+            "introduction": "You have more than one OpenZWave instance running. Which instance would you like to manage?",
+            "none_found": "We couldn't find an OpenZWave instance. If you believe this is incorrect, check your OpenZWave and MQTT setups and ensure that Home Assistant can communicate with your MQTT broker."
           },
           "network": {
             "header": "Network Management",