I'm getting following error while searching for NS record such as sales order or customer.

My code (BTW This code is functional and I started observing the error since y'day) Error line is marked in red.
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TransactionSearch xactionSearch = new TransactionSearch();
SearchEnumMultiSelectField soField = new SearchEnumMultiSelectField();
soField.setOperator(SearchEnumMultiSelectFieldOperator.anyOf);
String[] searchValueStringArray = new String[1];
searchValueStringArray[0] = tranType.toString();
soField.setSearchValue(searchValueStringArray);
SearchMultiSelectField intIdField = new SearchMultiSelectField();
intIdField.setOperator(SearchMultiSelectFieldOperator.noneOf);
RecordRef rr = new RecordRef();
rr.setInternalId("@NONE@");
rr.setType(RecordType.salesOrder);
RecordRef[] searchValueStringArray1 = new RecordRef[1];
searchValueStringArray1[0] = rr;
intIdField.setSearchValue(searchValueStringArray1);
TransactionSearchBasic xactionBasic = new TransactionSearchBasic();
xactionBasic.setType(soField);
xactionBasic.setInternalId(intIdField);
xactionSearch.setBasic(xactionBasic);