A potentially dangerous Request.Form value was detected from

A potentially dangerous Request.Form value was detected from the client …

Problem

The following “yellow screen” error occurs in your application:

A potentially dangerous Request.Form value was detected from the client

Description

Microsoft .NET Framework 1.1 causes this due to enhanced security features (request validation). Request Validation has detected a potentially dangerous client input value, and processing of the request has been aborted. This value may indicate an attempt to compromise the security of your application, such as a cross-site scripting attack. You can disable request validation by setting validateRequest=false in the Page directive or in the configuration section of Web.config. However, it is strongly recommended that your application explicitly check all inputs in this case.

Solution

Step 1: Locate the ASP.NET settings in:

<Application Folder>\Web.config

Step 2: Set the value of validateRequest attribute of pages element to false.