Patch-Magento_Ui-M2.1-attributeset.patch

diff --git a/view/base/web/js/form/element/multiselect.js b/view/base/web/js/form/element/multiselect.js
index 0876f3f..c001a3f 100644
--- a/view/base/web/js/form/element/multiselect.js
+++ b/view/base/web/js/form/element/multiselect.js
@@ -48,7 +48,7 @@ define([
          * @param {Array} data - current component value
          */
         setPrepareToSendData: function (data) {
-            if (!data.length) {
+            if (!data || !data.length) {
                 data = '';
             }