[ EDIT : Fixed at v1.5.2 ]

(Umbraco 7.3.4 / Vorto 1.5.1)

Created a datatype based on a Vorto wrapped RTE. Properties based on this datatype appear slow to load - the 'Loading...' text takes some time to clear - and if the RTE is left empty the log files show conversion errors during the loading and saving of documents, e.g.,

2016-04-06 08:35:11,205 [P5500/D2/T14] ERROR Our.Umbraco.Vorto.Web.PropertyEditors.VortoPropertyEditor+VortoPropertyValueEditor 
 - Error converting DB value to String
System.NullReferenceException: Object reference not set to an instance of an object.
   at Our.Umbraco.Vorto.Web.PropertyEditors.VortoPropertyEditor.VortoPropertyValueEditor.
   ConvertDbToString(Property property, PropertyType propertyType, IDataTypeService dataTypeService)
2016-04-06 08:35:11,252 [P5500/D2/T14] ERROR Our.Umbraco.Vorto.Web.PropertyEditors.VortoPropertyEditor+VortoPropertyValueEditor 
 - Error converting DB value to Editor
System.NullReferenceException: Object reference not set to an instance of an object.
   at Our.Umbraco.Vorto.Web.PropertyEditors.VortoPropertyEditor.VortoPropertyValueEditor.
   ConvertDbToEditor(Property property, PropertyType propertyType, IDataTypeService dataTypeService)

The xml corresponding to the empty property is stored in the db as:

<bodyTextVorto><![CDATA[{
  "dtdGuid": "1510ee86-759d-4645-ae0e-c4f62d2d4f24"
}]]></bodyTextVorto>

Once content is added to the RTE the errors clear, reappearing if the content is removed.

[Quick fix: for the moment, altered VortoPropertyEditor.cs to return empty string if the deserialized value.Values is null]

Great package by the way.

Angus