Guard against a null Meta property in the scale event API

ui/app/serializers/application.js

@@ -20,6 +20,17 @@ export default class Application extends JSONSerializer {
    */
   arrayNullOverrides = null;
 
+  /**
+    A list of keys that are converted to empty objects if their value is null.
+
+    objectNullOverrides = ['Object'];
+    { Object: null } => { Object: {} }
+
+    @property objectNullOverrides
+    @type String[]
+   */
+  objectNullOverrides = null;
+
   /**
     A list of keys or objects to convert a map into an array of maps with the original map keys as Name properties.
 
@@ -90,6 +101,13 @@ export default class Application extends JSONSerializer {
           }
         });
       }
+      if (this.objectNullOverrides) {
+        this.objectNullOverrides.forEach(key => {
+          if (!hash[key]) {
+            hash[key] = {};
+          }
+        });
+      }
 
       if (this.mapToArray) {
         this.mapToArray.forEach(conversion => {

ui/app/serializers/scale-event.js

@@ -2,4 +2,5 @@ import ApplicationSerializer from './application';
 
 export default class ScaleEventSerializer extends ApplicationSerializer {
   separateNanos = ['Time'];
+  objectNullOverrides = ['Meta'];
 }