Fixes #383

Author: justin-schroeder

src/FormulateGrouping.vue

@@ -7,7 +7,7 @@
   >
     <FormulateRepeatableProvider
       v-for="(item, index) in items"
-      :key="item.__id"
+      :key="index"
       :index="index"
       :context="context"
       :uuid="item.__id"

src/libs/registry.js

@@ -301,7 +301,7 @@ export function useRegistryMethods (without = []) {
     },
     setValues (values) {
       // Collect all keys, existing and incoming
-      const keys = Array.from(new Set(Object.keys(values).concat(Object.keys(this.proxy))))
+      const keys = Array.from(new Set(Object.keys(values || {}).concat(Object.keys(this.proxy))))
       keys.forEach(field => {
         const input = this.registry.has(field) && this.registry.get(field)
         let value = values[field]