In Umbraco v4.0.3 I needed to delete a data type I created. Once the data type had been deleted I tried modifying the document type which had a property using the deleted data type, and an error occurred:
Node node exists with id '1609'.
After a lot of searching it seems Umbraco did not delete a record in cmsPropertyType with the dataTypeId = 1609 - the data type I deleted. After deleting this record I could modify the document type without getting an error.
