SSRS Sub-Report Won't Load Until Refresh

I have an SSRS 2008 report with a sub-report that takes a selected value as a parameter. For example, I have a report that takes in @ProjectID and then selects ClientID. If I pass [ClientID] as a parameter to the sub report I get an error the first time I load the report. However, subsequent loads (clicking refresh) all work fine. I do not have this problem if I pass the parameter directly to the sub-report, ie [@ProjectID].

Is SSRS passing along para开发者_如何学Gometers before the select is issued so it's only working when it caches the values upon refreshing? Is there any way I can fix this without forcing all sub-reports to take in [@ProjectID]?

I figured this out. It did indeed appear to be an error with trying to populate the parameters before the query was run. I solved this by placing the sub-reports in a table which appears to delay rendering until the query has completed.