An error may be displayed when deploying reports using Microsoft Reporting Services containing IDAutomation .NET Windows Forms Controls. The error will look similar to:

Failed to load expression host assembly. Details: Request for the permission of type System.Security.Permissions.UIPermission, IDAutomation.LinearBarcode.dll, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b77a5c561934e089 failed. (rsProcessingError)

This error is generated when the .NET Forms Controls (or any other custom assembly used in a Reporting Services report) lack the proper permissions for execution on the machine distributing the report.

Solution(s):

Microsoft outlines the steps to assign permissions in the .NET Framework to custom assemblies needed in Reporting Services in the Microsoft Knowledge Base Article 842419.

This tutorial describes how to add barcode images to reports from .NET Windows Forms Controls.