diff --git a/webapp/src/App.vue b/webapp/src/App.vue
index b798e568..cc28983b 100644
--- a/webapp/src/App.vue
+++ b/webapp/src/App.vue
@@ -214,7 +214,7 @@ export default {
       try {
         await this.$store.dispatch("wot/fetchThingDescriptions", `${baseUri}/thing_descriptions/`);
         for (let requiredThing of ["camera", "stage"]) {
-          if (!this.$store.getters["wot/thingAvailable"](requiredThing)) {
+          if (!this.thingAvailable(requiredThing)) {
             throw new Error(`No ${requiredThing} found, the GUI won't work without one.`);
           }
         }
diff --git a/webapp/src/components/modalComponents/calibrationWizard.vue b/webapp/src/components/modalComponents/calibrationWizard.vue
index 6deb09ed..687263d8 100644
--- a/webapp/src/components/modalComponents/calibrationWizard.vue
+++ b/webapp/src/components/modalComponents/calibrationWizard.vue
@@ -78,13 +78,11 @@ export default {
       const calibrateableThings = Object.keys(this.availableCalibrationTasks);
 
       for (const name of calibrateableThings) {
-        try {
+        if (this.thingPropertyAvailable(name, "calibration_required")) {
           const thingNeedsCal = await this.readThingProperty(name, "calibration_required");
           if (thingNeedsCal) {
             needsCalibration.push(name);
           }
-        } catch (e) {
-          console.error(`${name}: missing calibration_required property`, e);
         }
       }
 
diff --git a/webapp/src/components/tabContentComponents/aboutComponents/statusPane.vue b/webapp/src/components/tabContentComponents/aboutComponents/statusPane.vue
index 2a045bb2..3a04754d 100644
--- a/webapp/src/components/tabContentComponents/aboutComponents/statusPane.vue
+++ b/webapp/src/components/tabContentComponents/aboutComponents/statusPane.vue
@@ -34,18 +34,16 @@
       <div class="uk-margin-small-bottom">
         <b>Camera:</b>
         <br />
-        <div v-if="'camera' in things">
-          {{ things.camera.title }}
+        <div>
+          {{ cameraType }}
         </div>
-        <div v-else class="uk-text-danger"><b>No camera configured</b></div>
       </div>
-      <div>
+      <div v-if="stageType">
         <b>Stage:</b>
         <br />
-        <div v-if="'stage' in things">
-          {{ things.stage.title }}
+        <div>
+          {{ stageType }}
         </div>
-        <div v-else class="uk-text-danger"><b>No stage configured</b></div>
       </div>
 
       <hr />
@@ -71,8 +69,12 @@ export default {
   },
 
   computed: {
-    things: function () {
-      return this.$store.getters["wot/thingDescriptions"];
+    cameraType() {
+      // No need to check as the microscope won't start up without a camera defined
+      return this.thingDescription("camera").title;
+    },
+    stageType() {
+      return this.thingAvailable("stage") ? this.thingDescription("stage").title : undefined;
     },
   },
 
diff --git a/webapp/src/components/tabContentComponents/powerContent.vue b/webapp/src/components/tabContentComponents/powerContent.vue
index ecb1c419..a1a6de49 100644
--- a/webapp/src/components/tabContentComponents/powerContent.vue
+++ b/webapp/src/components/tabContentComponents/powerContent.vue
@@ -10,7 +10,7 @@
     </p>
     <div class="buttons-container">
       <button
-        v-show="'shutdown' in things.system.actions"
+        v-show="shutdownAvailable"
         class="uk-button uk-button-primary uk-width-1-3 shutdown-button"
         @click="systemRequest('shutdown')"
       >
@@ -42,8 +42,8 @@ export default {
   },
 
   computed: {
-    things: function () {
-      return this.$store.getters["wot/thingDescriptions"];
+    shutdownAvailable() {
+      return this.thingActionAvailable("system", "shutdown");
     },
   },
 
diff --git a/webapp/src/components/tabContentComponents/scanListContent.vue b/webapp/src/components/tabContentComponents/scanListContent.vue
index bf85dd44..09f731c0 100644
--- a/webapp/src/components/tabContentComponents/scanListContent.vue
+++ b/webapp/src/components/tabContentComponents/scanListContent.vue
@@ -119,12 +119,7 @@ export default {
 
   computed: {
     scansUri() {
-      return this.$store.getters["wot/thingPropertyUrl"](
-        "smart_scan",
-        "scans",
-        "readproperty",
-        true,
-      );
+      return this.thingPropertyUrl("smart_scan", "scans");
     },
     scansEmpty() {
       return this.scans.length == 0;
diff --git a/webapp/src/components/tabContentComponents/settingsComponents/CSMSettingsComponents/CSMCalibrationSettings.vue b/webapp/src/components/tabContentComponents/settingsComponents/CSMSettingsComponents/CSMCalibrationSettings.vue
index fc3359c4..1aea1b80 100644
--- a/webapp/src/components/tabContentComponents/settingsComponents/CSMSettingsComponents/CSMCalibrationSettings.vue
+++ b/webapp/src/components/tabContentComponents/settingsComponents/CSMSettingsComponents/CSMCalibrationSettings.vue
@@ -69,10 +69,10 @@ export default {
 
   computed: {
     actions() {
-      return this.$store.getters["wot/thingDescription"]("camera_stage_mapping").actions;
+      return this.thingDescription("camera_stage_mapping").actions;
     },
     properties() {
-      return this.$store.getters["wot/thingDescription"]("camera_stage_mapping").properties;
+      return this.thingDescription("camera_stage_mapping").properties;
     },
   },
 
diff --git a/webapp/src/components/tabContentComponents/settingsComponents/cameraSettingsComponents/cameraCalibrationSettings.vue b/webapp/src/components/tabContentComponents/settingsComponents/cameraSettingsComponents/cameraCalibrationSettings.vue
index 9bc847de..80d674e6 100644
--- a/webapp/src/components/tabContentComponents/settingsComponents/cameraSettingsComponents/cameraCalibrationSettings.vue
+++ b/webapp/src/components/tabContentComponents/settingsComponents/cameraSettingsComponents/cameraCalibrationSettings.vue
@@ -52,7 +52,7 @@ export default {
 
   computed: {
     actions() {
-      return this.$store.getters["wot/thingDescription"]("camera").actions;
+      return this.thingDescription("camera").actions;
     },
   },
 
diff --git a/webapp/src/main.js b/webapp/src/main.js
index c60a7563..fb582300 100644
--- a/webapp/src/main.js
+++ b/webapp/src/main.js
@@ -36,13 +36,27 @@ Vue.mixin({
     thingAvailable(thing) {
       return this.$store.getters["wot/thingAvailable"](thing);
     },
-    async readThingProperty(thing, property, silence_errors = false) {
+    thingPropertyUrl(thing, property, allowUndefined = false) {
+      return this.$store.getters["wot/thingPropertyUrl"](
+        thing,
+        property,
+        "readproperty",
+        allowUndefined,
+      );
+    },
+    thingActionAvailable(thing, action) {
+      return this.$store.getters["wot/thingAffordanceAvailable"](thing, "actions", action);
+    },
+    thingPropertyAvailable(thing, property) {
+      return this.$store.getters["wot/thingAffordanceAvailable"](thing, "properties", property);
+    },
+    async readThingProperty(thing, property, silenceErrors = false) {
       let url = this.$store.getters["wot/thingPropertyUrl"](thing, property, "readproperty", false);
       try {
         let response = await axios.get(url);
         return response.data;
       } catch (error) {
-        if (!silence_errors) this.modalError(error);
+        if (!silenceErrors) this.modalError(error);
         return undefined;
       }
     },
@@ -71,12 +85,12 @@ Vue.mixin({
         return undefined;
       }
     },
-    thingActionUrl(thing, action, allow_missing = false) {
+    thingActionUrl(thing, action, allowUndefined = false) {
       let url = this.$store.getters["wot/thingActionUrl"](
         thing,
         action,
         "invokeaction",
-        allow_missing,
+        allowUndefined,
       );
       return url;
     },
diff --git a/webapp/src/wot-client.js b/webapp/src/wot-client.js
index ab717ee9..354fcd5e 100644
--- a/webapp/src/wot-client.js
+++ b/webapp/src/wot-client.js
@@ -57,6 +57,13 @@ export const wotStoreModule = {
     thingAvailable: (state) => (thingName) => {
       return thingName in state.thingDescriptions;
     },
+    thingAffordanceAvailable: (state) => (thing, affordanceType, affordance) => {
+      let td = state.thingDescriptions[thing];
+      if (!td) {
+        return false;
+      }
+      return affordance in td[affordanceType];
+    },
     thingFormUrl:
       (state) =>
       (thing, affordanceType, affordance, op, allowUndefined = true) => {