Variable Name must not be null

[kyle Hailey]

running into an error

            java.lang.IllegalArgumentException: Variable Name must not be
null

for simple statement like

     delete from authors where id in (  select id from authors limit 1 )

Any thoughts? I've googled around and not found much.
I have it set up as an "Query Type :  Update Statement"
Not sure if that's right. Haven't found much info on query type.

This query works fine in psql

Thanks
Kyle