Error when validating report

[vlfoley]

RQP-DEF-0177 An error occurred while performing operation 'sqlPrepareWithOptions' status='-56'.
UDA-SQL-0115 Inappropriate SQL request.
UDA-SQL-0564 [Microsoft OLE DB Provider for SQL Server]Deferred prepare could not be completed.
UDA-SQL-0564 [Microsoft OLE DB Provider for SQL Server]Statement(s) could not be prepared. (SQLSTATE=42000, SQLERRORCODE=8180)
UDA-SQL-0564 [Microsoft OLE DB Provider for SQL Server]Operand data type varchar is invalid for sum operator. (SQLSTATE=42000, SQLERRORCODE=8117)


I have created a new data item in the Query Explorer of Report Studio, the data item is called Total Cost. The data item consists of...[Business Logic View].[Workorder].[ACTMATCOST] + [Business Logic View].[Workorder].[ACTLABCOST] + [Business Logic View].[Workorder].[ACTTOOLCOST] + [Business Logic View].[Workorder].[ACTSERVCOST]

I notice that deep in that error message it says 'Operand data type varchar is invalid for sum operator'. Those fields are not varchar. They are all decimal data type. Cognos recognizes them as numbers. But I'm still receiving that error. I tried creating a Query Calculation in the Page Explorer of Report Studio but still received the same error. I've tried casting the information as a double or an integar and I still receive that error. Not sure what to do from here.

[Arsenal]

one of the first things I would try is deleting this data item and hitting the validate button again to find out if indeed it is this particular data item causing the error.

if this dataitem is only doing a sum of all numbers, it can't be causing the error