My query, simplified greatly, note that the data source is Oracle 11g, selected the "Oracle" type for the data source type. SELECT EMPLID, ROW_NUMBER() OVER (PARTITION BY a.EMPLID ORDER BY a.EMPL_RCD DESC) rNum <------- FROM SA.CC_SM_HR_ALL a The rnum field is actually giving me issues - note that when i create a simple tablix with no row groups except details, with emplid and rnum I get #Error in the rnum field, in spite of the fact that it is always populated with an integer between 1 and 45. The errors I get in BIDs Error messages are: Warning 84 [rsRuntimeErrorInExpression] The Value expression for the textrun RNUM.Paragraphs[0].TextRuns[0] contains an error: No default member found for type 'CalculatedFieldWrapperImpl'. Warning 85 [rsInvalidExpressionDataType] The Value expression used in textrun RNUM1.Paragraphs[0].TextRuns[0] returned a data type that is not valid.

Hi There Thanks for your posting. Can you please try to put expression like this in the textbox expression =Fields!RNUm.value.tostring Many thanks Syed Qazafi

Hello baal32, Thank you to post your question on TechNet forum. First, I want to check whether the PL-SQL query is correct. Please try to run the query into Oracle 11g to see whether there are any errors. If possible, please try the following query on your side to see whether it works or not. SELECT EMPLID, a.EMPL_RCD ROW_NUMBER() OVER (PARTITION BY a.EMPLID ORDER BY a.EMPL_RCD DESC) rNum FROM SA.CC_SM_HR_ALL a Since we do not have Oracle database, I did not test it. Regards, EdwardEdward Zhu TechNet Community Support

Sorry for the late reply. I eventually gave up and recreated the report with the same query and it worked. This seems to be similar to another SSRS bug that a colleague reported, basically that when columns are added to the dataset after the tablix has already been defined, even though the refresh fields shows the new columns for some reason the tablix seems to be retaining the old structure of the dataset and as such tries to use the column that was at position n even if the column now occupies position k. So for instance if I have select number, date from table and create a tablix displaying just number, but then change the dataset to select string, number, date from table the tablix tries to display the string field becuase it is occupying the position where the number used to be - the only solution seems to be to recreate the report from scratch.