Null pointer exception

[annavalentina]

I create a connection with druid. I can access the schema of the datasource without any problem but when I execute a sql query and try to print the results I get a Null pointer exception even though if I execute the same query through the UI I get results. The druid version is 0.17 and the Spark version 2.3.1. Is this a version issue or something else? Thank you in advance