message: Can't complete survey with required HTML question
diff: @@ -47,13 +47,13 @@ Serializer.addClass(
  { name: "enableIf", visible: false },
  { name: "defaultValue", visible: false },
  { name: "correctAnswer", visible: false },
  - { name: "isRequired", visible: false },
  + { name: "isRequired", visible: false, isSerializable: false },
  { name: "requiredErrorText", visible: false },
  { name: "readOnly", visible: false },
  { name: "requiredIf", visible: false },
  { name: "validators", visible: false },
  { name: "titleLocation", visible: false },
  - { name: "useDisplayValuesInTitle", visible: false }
  + { name: "useDisplayValuesInTitle", visible: false },
  ],
  function () {
  return new QuestionNonValue("");
  