What kind of chart are you trying to create? a simple line chart? Chart type can be seen when you click on 'Property' node.
Well that can't be the query you are using since it has syntax errors.
and response_sent < TO_DATE( , 'YYYY-MM-DD') + 1
There is no value for the first parameter of that TO_DATE.
Post the correct query or if that is the query fix the syntax.
Fixed it....I think I found the problem though. The problem is: "trunc(response_sent, 'HH24')"
If I change this to an actual value like: TO_NUMBER(TO_CHAR(response_sent, 'HH24')) then it works. Maybe it can't take a date as an X value.
>> Maybe it can't take a date as an X value.
That sounds more than probable.