diff --git a/src/components/devices/OpenwbConfigProxy.vue b/src/components/devices/OpenwbConfigProxy.vue
index 91aeb3ab..442eb1e5 100644
--- a/src/components/devices/OpenwbConfigProxy.vue
+++ b/src/components/devices/OpenwbConfigProxy.vue
@@ -3,9 +3,9 @@
     :is="getComponent()"
     :device="device"
     :component="component"
-    :configuration="component ? component.configuration : device.configuration"
-    :device-id="device.id"
-    :device-type="device.type"
+    :configuration="component ? component.configuration : device?.configuration"
+    :device-id="device?.id"
+    :device-type="device?.type"
     :component-id="component ? component.id : undefined"
     :component-type="component ? component.type : undefined"
     @update:configuration="updateConfiguration($event)"
@@ -26,7 +26,7 @@ export default {
   emits: ["update:configuration"],
   methods: {
     getComponent() {
-      console.debug(`loading component: ${this.device.type} / ${this.component?.type}`);
+      console.debug(`loading component: ${this.device?.type} / ${this.component?.type}`);
       if (this.component !== undefined) {
         return defineAsyncComponent({
           loader: () => import(`./${this.device.vendor}/${this.device.type}/${this.component.type}.vue`),
@@ -34,7 +34,7 @@ export default {
         });
       } else {
         return defineAsyncComponent({
-          loader: () => import(`./${this.device.vendor}/${this.device.type}/device.vue`),
+          loader: () => import(`./${this.device.vendor}/${this.device?.type}/device.vue`),
           errorComponent: OpenwbDeviceConfigFallback,
         });
       }
diff --git a/src/views/ChargePointInstallation.vue b/src/views/ChargePointInstallation.vue
index 36e417c3..2a04e017 100644
--- a/src/views/ChargePointInstallation.vue
+++ b/src/views/ChargePointInstallation.vue
@@ -526,17 +526,22 @@ export default {
         let chargePoints = this.getWildcardTopics("openWB/chargepoint/+/config");
         let myObj = {};
         for (const [key, element] of Object.entries(chargePoints)) {
-          if (element.type === "internal_openwb" || this.$store.state.mqtt["openWB/general/extern"] === false) {
+          if (
+            element &&
+            typeof element === "object" &&
+            (element.type === "internal_openwb" || this.$store.state.mqtt["openWB/general/extern"] === false)
+          ) {
             myObj[key] = element;
           }
         }
         return myObj;
       },
     },
-    chargePointTemplates: {
-      get() {
-        return this.getWildcardTopics("openWB/chargepoint/template/+");
-      },
+    chargePointTemplates() {
+      const chargePointTemplates = this.getWildcardTopics("openWB/chargepoint/template/+");
+      return Object.fromEntries(
+        Object.entries(chargePointTemplates).filter(([, template]) => template && typeof template === "object"),
+      );
     },
     chargePointTemplateList: {
       get() {
diff --git a/src/views/HardwareInstallation.vue b/src/views/HardwareInstallation.vue
index 55cc7119..ac9969d4 100644
--- a/src/views/HardwareInstallation.vue
+++ b/src/views/HardwareInstallation.vue
@@ -62,10 +62,10 @@
               <div v-else>
                 <openwb-base-avatar
                   v-for="installedComponent in getMyInstalledComponents(installedDevice?.id)"
-                  :key="installedComponent.id"
-                  :class="'ml-1 bg-' + getComponentTypeClass(installedComponent.type)"
+                  :key="installedComponent?.id"
+                  :class="'ml-1 bg-' + getComponentTypeClass(installedComponent?.type)"
                 >
-                  <font-awesome-icon :icon="getComponentTypeIcon(installedComponent.type)" />
+                  <font-awesome-icon :icon="getComponentTypeIcon(installedComponent?.type)" />
                 </openwb-base-avatar>
               </div>
             </template>
@@ -89,15 +89,15 @@
               Es wurden noch keine Komponenten zu diesem Gerät angelegt.
             </openwb-base-alert>
             <openwb-base-card
-              v-for="(installedComponent, installedComponentKey) in getMyInstalledComponents(installedDevice.id)"
-              :key="installedComponent.id"
+              v-for="(installedComponent, installedComponentKey) in getMyInstalledComponents(installedDevice?.id)"
+              :key="installedComponent?.id"
               :collapsible="true"
               :collapsed="true"
-              :subtype="getComponentTypeClass(installedComponent.type)"
+              :subtype="getComponentTypeClass(installedComponent?.type)"
             >
               <template #header>
-                <font-awesome-icon :icon="getComponentTypeIcon(installedComponent.type)" />
-                {{ installedComponent.name }}
+                <font-awesome-icon :icon="getComponentTypeIcon(installedComponent?.type)" />
+                {{ installedComponent?.name }}
               </template>
               <template #actions="slotProps">
                 <openwb-base-avatar
@@ -105,10 +105,10 @@
                   class="bg-danger clickable"
                   @click="
                     removeComponentModal(
-                      installedDevice.id,
-                      installedComponent.id,
-                      installedComponent.type,
-                      installedComponent.name,
+                      installedDevice?.id,
+                      installedComponent?.id,
+                      installedComponent?.type,
+                      installedComponent?.name,
                       $event,
                     )
                   "
@@ -119,13 +119,13 @@
               <openwb-base-text-input
                 title="Bezeichnung"
                 subtype="text"
-                :model-value="installedComponent.name"
+                :model-value="installedComponent?.name"
                 @update:model-value="updateState(installedComponentKey, $event, 'name')"
               />
               <openwb-base-text-input
                 title="Hersteller"
                 subtype="text"
-                :model-value="installedComponent.info.manufacturer"
+                :model-value="installedComponent?.info.manufacturer"
                 @update:model-value="updateState(installedComponentKey, $event, 'info.manufacturer')"
               >
                 <template #help> Optional: zusätzliche Information für den Systembericht. </template>
@@ -133,7 +133,7 @@
               <openwb-base-text-input
                 title="Modell"
                 subtype="text"
-                :model-value="installedComponent.info.model"
+                :model-value="installedComponent?.info.model"
                 @update:model-value="updateState(installedComponentKey, $event, 'info.model')"
               >
                 <template #help> Optional: zusätzliche Information für den Systembericht. </template>
@@ -147,19 +147,19 @@
             </openwb-base-card>
             <hr />
             <openwb-base-select-input
-              v-if="getComponentList(installedDevice.vendor, installedDevice.type).length"
+              v-if="getComponentList(installedDevice?.vendor, installedDevice?.type)?.length"
               title="Verfügbare Komponenten"
               not-selected="Bitte auswählen"
-              :options="getComponentList(installedDevice.vendor, installedDevice.type)"
-              :model-value="componentToAdd[installedDevice.id]"
+              :options="getComponentList(installedDevice?.vendor, installedDevice?.type)"
+              :model-value="componentToAdd[installedDevice?.id]"
               :add-button="true"
-              @update:model-value="componentToAdd[installedDevice.id] = $event"
+              @update:model-value="componentToAdd[installedDevice?.id] = $event"
               @input:add="
                 addComponent(
-                  installedDevice.id,
-                  installedDevice.vendor,
-                  installedDevice.type,
-                  componentToAdd[installedDevice.id],
+                  installedDevice?.id,
+                  installedDevice?.vendor,
+                  installedDevice?.type,
+                  componentToAdd[installedDevice?.id],
                 )
               "
             >
@@ -175,7 +175,7 @@
               Dieses System bietet keine Komponenten zur Installation an.
             </openwb-base-alert>
           </openwb-base-card>
-          <hr v-if="Object.keys(installedDevices).length > 0" />
+          <hr v-if="Object.keys(installedDevices)?.length > 0" />
           <openwb-base-select-input
             v-model="selectedVendor"
             title="Hersteller"
@@ -282,36 +282,39 @@ export default {
     };
   },
   computed: {
-    installedDevices: {
-      get() {
-        return this.getWildcardTopics("openWB/system/device/+/config");
-      },
+    installedDevices() {
+      const installedDevices = this.getWildcardTopics("openWB/system/device/+/config");
+      return Object.fromEntries(
+        Object.entries(installedDevices).filter(([, template]) => template && typeof template === "object"),
+      );
     },
-    installedComponents: {
-      get() {
-        return this.getWildcardTopics("openWB/system/device/+/component/+/config");
-      },
+    installedComponents() {
+      const installedComponents = this.getWildcardTopics("openWB/system/device/+/component/+/config");
+      return Object.fromEntries(
+        Object.entries(installedComponents).filter(([, template]) => template && typeof template === "object"),
+      );
     },
     vendorList: {
       get() {
-        if (this.$store.state.mqtt["openWB/system/configurable/devices_components"] === undefined) {
+        const devicesComponents = this.$store.state.mqtt["openWB/system/configurable/devices_components"];
+        if (!devicesComponents) {
           return [];
         }
-        return Object.entries(this.$store.state.mqtt["openWB/system/configurable/devices_components"])
+        return Object.entries(devicesComponents)
           .map(([groupKey, group]) => {
+            // Fallback für group.vendors
+            const vendors = group?.vendors || {};
             return {
-              label: group.group_name,
-              options: Object.entries(group.vendors)
-                .map(([vendorKey, vendor]) => {
-                  return {
-                    value: [groupKey, vendorKey],
-                    text: vendor.vendor_name,
-                  };
-                })
+              label: group?.group_name || "",
+              options: Object.entries(vendors)
+                .map(([vendorKey, vendor]) => ({
+                  value: [groupKey, vendorKey],
+                  text: vendor?.vendor_name || "",
+                }))
                 .sort((a, b) => a.text.localeCompare(b.text)),
             };
           })
-          .sort((a, b) => -a.label.localeCompare(b.label)); // reverse order to have "openWB" at the top
+          .sort((a, b) => -a.label.localeCompare(b.label));
       },
     },
     deviceList: {
@@ -320,15 +323,17 @@ export default {
           return [];
         }
         let [groupKey, vendorKey] = this.selectedVendor;
-        return Object.entries(
-          this.$store.state.mqtt["openWB/system/configurable/devices_components"][groupKey].vendors[vendorKey].devices,
-        )
-          .map(([deviceKey, device]) => {
-            return {
-              value: [vendorKey, deviceKey],
-              text: device.device_name,
-            };
-          })
+        const devices =
+          this.$store.state.mqtt["openWB/system/configurable/devices_components"]?.[groupKey]?.vendors?.[vendorKey]
+            ?.devices;
+        if (!devices) {
+          return [];
+        }
+        return Object.entries(devices)
+          .map(([deviceKey, device]) => ({
+            value: [vendorKey, deviceKey],
+            text: device.device_name,
+          }))
           .sort((a, b) => a.text.localeCompare(b.text));
       },
     },
diff --git a/src/views/IoConfig.vue b/src/views/IoConfig.vue
index af83eec5..2fb27385 100644
--- a/src/views/IoConfig.vue
+++ b/src/views/IoConfig.vue
@@ -199,10 +199,11 @@ export default {
         return this.$store.state.mqtt["openWB/system/configurable/io_devices"];
       },
     },
-    installedIoDevices: {
-      get() {
-        return this.getWildcardTopics("openWB/system/io/+/config");
-      },
+    installedIoDevices() {
+      const installedIoDevices = this.getWildcardTopics("openWB/system/io/+/config");
+      return Object.fromEntries(
+        Object.entries(installedIoDevices).filter(([, template]) => template && typeof template === "object"),
+      );
     },
     ioActionList: {
       get() {
diff --git a/src/views/MqttBridgeConfig.vue b/src/views/MqttBridgeConfig.vue
index 1961c112..4e3c845e 100644
--- a/src/views/MqttBridgeConfig.vue
+++ b/src/views/MqttBridgeConfig.vue
@@ -47,7 +47,7 @@
           :name="'mqttBridgeConfigurationForm' + getMqttBridgeIndex(mqttBridgeKey)"
         >
           <openwb-base-card
-            :title="mqttBridge.name"
+            :title="mqttBridge?.name"
             :collapsible="true"
             :collapsed="true"
             subtype="primary"
@@ -65,7 +65,7 @@
               subtype="text"
               required
               pattern="[A-Za-z0-9]+"
-              :model-value="mqttBridge.name"
+              :model-value="mqttBridge?.name"
               @update:model-value="updateState(mqttBridgeKey, $event, 'name')"
             >
               <template #help> Die Bezeichnung darf nur aus Buchstaben ohne Umlaute und Zahlen bestehen. </template>
@@ -84,7 +84,7 @@
                   class: 'btn-outline-success',
                 },
               ]"
-              :model-value="mqttBridge.active"
+              :model-value="mqttBridge?.active"
               @update:model-value="updateState(mqttBridgeKey, $event, 'active')"
             />
             <hr />
@@ -93,7 +93,7 @@
               title="Entfernter Server"
               subtype="host"
               required
-              :model-value="mqttBridge.remote.host"
+              :model-value="mqttBridge?.remote?.host"
               @update:model-value="updateState(mqttBridgeKey, $event, 'remote.host')"
             />
             <openwb-base-number-input
@@ -101,7 +101,7 @@
               required
               :min="1"
               :max="65535"
-              :model-value="mqttBridge.remote.port"
+              :model-value="mqttBridge?.remote?.port"
               @update:model-value="updateState(mqttBridgeKey, $event, 'remote.port')"
             />
             <openwb-base-text-input
@@ -109,21 +109,21 @@
               subtype="user"
               required
               pattern="[a-zA-Z0-9_\-+.]+"
-              :model-value="mqttBridge.remote.username"
+              :model-value="mqttBridge?.remote?.username"
               @update:model-value="updateState(mqttBridgeKey, $event, 'remote.username')"
             />
             <openwb-base-text-input
               title="Passwort"
               subtype="password"
               required
-              :model-value="mqttBridge.remote.password"
+              :model-value="mqttBridge?.remote?.password"
               @update:model-value="updateState(mqttBridgeKey, $event, 'remote.password')"
             />
             <openwb-base-text-input
               title="Präfix"
               subtype="text"
               pattern="[A-Za-z0-9_\-]+(\/[A-Za-z0-9_\-]+)?\/"
-              :model-value="mqttBridge.remote.prefix"
+              :model-value="mqttBridge?.remote?.prefix"
               @update:model-value="updateState(mqttBridgeKey, $event, 'remote.prefix')"
             >
               <template #help>
@@ -137,7 +137,7 @@
               subtype="text"
               required
               pattern="[A-Za-z0-9_\-]+"
-              :model-value="mqttBridge.remote.client_id"
+              :model-value="mqttBridge?.remote?.client_id"
               @update:model-value="updateState(mqttBridgeKey, $event, 'remote.client_id')"
             >
               <template #help>
@@ -157,7 +157,7 @@
                   text: 'v3.1.1',
                 },
               ]"
-              :model-value="mqttBridge.remote.protocol"
+              :model-value="mqttBridge?.remote?.protocol"
               @update:model-value="updateState(mqttBridgeKey, $event, 'remote.protocol')"
             />
             <openwb-base-button-group-input
@@ -183,7 +183,7 @@
                   text: 'v1.2',
                 },
               ]"
-              :model-value="mqttBridge.remote.tls_version"
+              :model-value="mqttBridge?.remote?.tls_version"
               @update:model-value="updateState(mqttBridgeKey, $event, 'remote.tls_version')"
             >
               <template #help>
@@ -206,7 +206,7 @@
                   class: 'btn-outline-success',
                 },
               ]"
-              :model-value="mqttBridge.remote.try_private"
+              :model-value="mqttBridge?.remote?.try_private"
               @update:model-value="updateState(mqttBridgeKey, $event, 'remote.try_private')"
             >
               <template #help>
@@ -232,7 +232,7 @@
                   class: 'btn-outline-success',
                 },
               ]"
-              :model-value="mqttBridge.data_transfer.status"
+              :model-value="mqttBridge?.data_transfer?.status"
               @update:model-value="updateState(mqttBridgeKey, $event, 'data_transfer.status')"
             >
               <template #help>
@@ -254,7 +254,7 @@
                   class: 'btn-outline-success',
                 },
               ]"
-              :model-value="mqttBridge.data_transfer.graph"
+              :model-value="mqttBridge?.data_transfer?.graph"
               @update:model-value="updateState(mqttBridgeKey, $event, 'data_transfer.graph')"
             >
               <template #help>
@@ -279,7 +279,7 @@
                   class: 'btn-outline-success',
                 },
               ]"
-              :model-value="mqttBridge.data_transfer.configuration"
+              :model-value="mqttBridge?.data_transfer?.configuration"
               @update:model-value="updateState(mqttBridgeKey, $event, 'data_transfer.configuration')"
             >
               <template #help>
@@ -331,13 +331,17 @@ export default {
   computed: {
     configuredMqttBridges: {
       get() {
-        let bridges = this.getWildcardTopics("openWB/system/mqtt/bridge/+");
-        for (const [key, value] of Object.entries(bridges)) {
-          if (value.remote.is_openwb_cloud) {
-            delete bridges[key];
+        const bridges = this.getWildcardTopics("openWB/system/mqtt/bridge/+");
+        if (!bridges || typeof bridges !== "object") {
+          return {};
+        }
+        const filtered = { ...bridges };
+        for (const [key, value] of Object.entries(filtered)) {
+          if (value?.remote?.is_openwb_cloud) {
+            delete filtered[key];
           }
         }
-        return bridges;
+        return filtered;
       },
     },
   },
diff --git a/src/views/VehicleConfig.vue b/src/views/VehicleConfig.vue
index 764971be..c71c0914 100644
--- a/src/views/VehicleConfig.vue
+++ b/src/views/VehicleConfig.vue
@@ -96,7 +96,7 @@
             <openwb-base-text-input
               v-if="vehicleId !== 0"
               title="Fahrzeughersteller "
-              :model-value="$store.state.mqtt['openWB/vehicle/' + vehicleId + '/info'].manufacturer"
+              :model-value="$store.state.mqtt['openWB/vehicle/' + vehicleId + '/info']?.manufacturer"
               @update:model-value="updateState('openWB/vehicle/' + vehicleId + '/info', $event, 'manufacturer')"
             >
               <template #help> Optional: zusätzliche Information für den Systembericht. </template>
@@ -104,7 +104,7 @@
             <openwb-base-text-input
               v-if="vehicleId !== 0"
               title="Fahrzeugmodell"
-              :model-value="$store.state.mqtt['openWB/vehicle/' + vehicleId + '/info'].model"
+              :model-value="$store.state.mqtt['openWB/vehicle/' + vehicleId + '/info']?.model"
               @update:model-value="updateState('openWB/vehicle/' + vehicleId + '/info', $event, 'model')"
             >
               <template #help>
@@ -132,7 +132,7 @@
             <hr />
             <div v-if="!installAssistantActive">
               <openwb-base-heading> Fahrzeugzuordnung per ID-Tags </openwb-base-heading>
-              <div v-if="$store.state.mqtt['openWB/vehicle/' + vehicleId + '/tag_id'].length > 0">
+              <div v-if="($store.state.mqtt['openWB/vehicle/' + vehicleId + '/tag_id']?.length ?? 0) > 0">
                 <openwb-base-alert subtype="info">
                   Einstellungen zur Fahrzeugzuordnung finden sich unter
                   <router-link to="/IdentificationConfig"> Einstellungen - Identifikation </router-link>.
@@ -169,7 +169,7 @@
               class="mb-2"
               title="SoC-Modul des Fahrzeugs"
               :options="socModuleList"
-              :model-value="$store.state.mqtt['openWB/vehicle/' + vehicleId + '/soc_module/config'].type"
+              :model-value="$store.state.mqtt['openWB/vehicle/' + vehicleId + '/soc_module/config']?.type"
               @update:model-value="updateSelectedSocModule(vehicleId, $event)"
             >
               <template #help>
@@ -189,7 +189,7 @@
                 infolge von zeitlicher Verzögerungen kommen. Hilfestellung erfolgt primär im openWB-Forum.
               </template>
             </openwb-base-select-input>
-            <div v-if="$store.state.mqtt['openWB/vehicle/' + vehicleId + '/soc_module/config'].type">
+            <div v-if="$store.state.mqtt['openWB/vehicle/' + vehicleId + '/soc_module/config']?.type">
               <openwb-base-button-group-input
                 title="SoC direkt aus Fahrzeug auslesen"
                 :buttons="[
@@ -205,7 +205,7 @@
                   },
                 ]"
                 :model-value="
-                  $store.state.mqtt['openWB/vehicle/' + vehicleId + '/soc_module/general_config'].use_soc_from_cp
+                  $store.state.mqtt['openWB/vehicle/' + vehicleId + '/soc_module/general_config']?.use_soc_from_cp
                 "
                 @update:model-value="
                   updateState('openWB/vehicle/' + vehicleId + '/soc_module/general_config', $event, 'use_soc_from_cp')
@@ -233,7 +233,7 @@
                 required
                 :model-value="
                   $store.state.mqtt['openWB/vehicle/' + vehicleId + '/soc_module/general_config']
-                    .request_interval_charging / 60
+                    ?.request_interval_charging / 60
                 "
                 @update:model-value="
                   updateState(
@@ -1484,10 +1484,13 @@ export default {
         return this.getWildcardIndexList("openWB/vehicle/+/name");
       },
     },
-    evTemplates: {
-      get() {
-        return this.getWildcardTopics("openWB/vehicle/template/ev_template/+");
-      },
+    evTemplates() {
+      const evTemplates = this.getWildcardTopics("openWB/vehicle/template/ev_template/+");
+      return Object.fromEntries(
+        // Filter out temporarily undefined entries caused by async MQTT (unsubscribe/resubscribe),
+        // (on button push, discard changes) so templates never try to render incomplete data.
+        Object.entries(evTemplates).filter(([, template]) => template && typeof template === "object"),
+      );
     },
     evTemplateList: {
       get() {
@@ -1500,10 +1503,13 @@ export default {
         return myList;
       },
     },
-    chargeTemplates: {
-      get() {
-        return this.getWildcardTopics("openWB/vehicle/template/charge_template/+");
-      },
+    chargeTemplates() {
+      const chargeTemplates = this.getWildcardTopics("openWB/vehicle/template/charge_template/+");
+      return Object.fromEntries(
+        // Filter out temporarily undefined entries caused by async MQTT (unsubscribe/resubscribe),
+        // (on button push, discard changes) so templates never try to render incomplete data.
+        Object.entries(chargeTemplates).filter(([, template]) => template && typeof template === "object"),
+      );
     },
     chargeTemplateList: {
       get() {