FIX: Duplicate records in the report rendering when you use Lookup function in the expression of a matrix in SSRS 2012 or SSRS 2014


Symptoms


Assume that you use Microsoft SQL Server 2012 Reporting Services (SSRS 2012) Service Pack 1 (SP1) Cumulative Update 8 (CU8) or a later version. When you build a matrix with text box and use the Lookup function in its expression, duplicate records occur in the report rendering.

Resolution


The issue was first fixed in the following cumulative update of SQL Server.

Cumulative Update 1 for SQL Server 2014 SP1

Cumulative Update 6 for SQL Server 2014

Cumulative Update 3 for SQL Server 2012 SP2

Status


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.