Parser Error: Could not load file or assembly System.Web.Abstractions, Version=3.5.0.0

Problem

You get this error when running your application:

Parser Error: Could not load file or assembly 'System.Web.Abstractions, Version=3.5.0.0

This error occurs when your system is running Microsoft .NET Framework 3.5 without Service Pack 1 (SP1) or later installed.

Solution

Install Service Pack 1 (SP1) or later for .NET Framework 3.5..

See Also

Part IX:  Troubleshooting Applications

Application Will Not Run

Application Runs But No Data is Displayed

Application Error Messages