I am working in 2008 R2. I have a piece of RDL that has been working, including the following block: <SortExpressions> <SortExpression> <Value>=IIf(Code.GetParameterValue("SortPackagesSellingTitles") = "Chronologically", Fields!SELL_TITLE_DISPLAY_ORDER.Value, Fields!SELL_TITLE_NAME.Value)</Value> </SortExpression> </SortExpressions> When I add the following Filter Expression, I get the error: Failed to evaluate the FilterExpression of the Grouping GroupSellTitle <Group Name="GroupSellTitle"> <GroupExpressions> <GroupExpression>=Fields!SELL_TITLE_NAME.Value</GroupExpression> </GroupExpressions> <Filters> <Filter> <FilterExpression>=IIf(Code.GetParameterValue("IncludeSellingTitles") = "Y", true, false) </FilterExpression> <Operator>Equal</Operator> <FilterValues> <FilterValue DataType="Boolean">=true</FilterValue> </FilterValues> </Filter> </Filters> </Group> If I remove the custom code and substitute a dummy expression, such as =1=2, the code runs successfully (and, of course, filters out all the data for that group). It seems as if FilterExpression is not allowing me to use custom code (that other expressions in the code will allow me to use). Or is the problem something else I am not thinking of? Thanks for thinking about my question. Let me know if you need more info.

Hi Joe Schmeaux, I have tried a simple custom code in FilterExpression with my report, and it works well, so that, custom code can be used in FilterExpression in report. There must be a <Filter> element with a filter value expression somewhere in the report that doesn't correctly reflect the logic you described above for your report, and therefore fails with an exception during expression evaluation when you run the report. If possible, could you please send your RDL file with simple data structure? Once I receive your email, I will give you a feedback as soon as possible. E-mail: sqltnsp AT Microsoft.com (Please replace AT with @). Please send me with the following format: Subject: MSDN/TechNet forum question: <Thread Title> Attachments: <files> Hi Eileen, ThreadURL:<URL> <Additional information> If you have any question, please feel free to ask. Thanks, Eileen