diff --git a/Code.gs b/Code.gs
index 8cc7dab..625ad92 100644
--- a/Code.gs
+++ b/Code.gs
@@ -9,7 +9,7 @@
  * - use google auth with token based Jira RESTful API vs. cleartext password
  */
 
-var BUILD = '0.20.3';
+var BUILD = '0.20.4';
 
 /** 
  * Add a nice menu option for the users.
diff --git a/dialogCustomFields.html b/dialogCustomFields.html
index 22a0f96..6ed35bb 100644
--- a/dialogCustomFields.html
+++ b/dialogCustomFields.html
@@ -95,21 +95,26 @@
         });
         window.dispatchEvent(new Event('load'));
       }
+
       function updFavoriteField() {
         var add = (this.name === 'customfield') && this.checked;
-        
+
         // add custom field to favorites
         if (add) {
           addFavoriteItem(JSON.parse(this.value));
         }
+
         // remove custom field from favorites
         if (!this.checked) {
-          var field = JSON.parse(this.value);
-          form.querySelector('#customfield-id-' + field.key).checked = false;
+          var cfield, field = JSON.parse(this.value);
+          if (cfield = form.querySelector('#customfield-id-' + field.key)) {
+            cfield.checked = false;
+          }
           var el = form.querySelector('#favoriteField-'  + field.key);
           el.parentNode.parentNode.removeChild(el.parentNode);
         }
       }
+
       function addFavoriteItem(item) {
         var chkbox      = document.createElement('div');
         var chkboxInput = document.createElement('input');
@@ -160,10 +165,13 @@
       function isFavorite(key) {
         return _storedFavFields.find(o => o.key === key);
       }
+
       google.script.run
         .withSuccessHandler(onInitCustomFields)
         .fetchCustomFields();
+
       form.addEventListener('submit', formSubmitHandler);
+
       window.addEventListener('load', function(){
         Array.prototype.slice.call(form.elements).filter(function(el){ 
           if(el.nodeName === 'INPUT' && el.type === 'checkbox') {