This Extractor says that when using it, some criteria on the field BUDAT is required. Not sure about DataPreview but
when importing in CDC mode, add a filter criteria on the BUDAT column
when having imported it in query mode, make sure you specify a where clause in the downstream query on BUDAT
If the first was done and you still got an error, try adding a filter on BUDAT in the data preview dialog an refresh
If all of that does not help, please file a bug stating that “some Extractors require a mandatory selection criteria and DataPreview does not work hence”