Normally you will encounter the above error when you intend to make your parameter as a selection (dropdown) as follows:
When developers try it in the first time and use Available Value in Report Parameters dialog then they will normally get an error that is close to this:
The report parameter ‘sales’ has a DefaultValue or a ValidValue that depends on the report parameter “sales”. Forward dependencies are not valid.
It is uneasy to find this error in Internet. Look at the below picture closely:
The answer is not that hard. You need to use 2 Datasets instead of one. As in the picture I have dbconn (the query with parameter) and dsAllCall (query that return all the rows).
It is hard to find this approach in Reporting Services documented mainly because using 2 Datasets is usually slow if and when you have huge amount of rows.
How to: Associate a Query Parameter with a Report Parameter
Developing Report Navigation and Drilldown