ASP.NET Request Validation Exception Even When Validation Is Disabled

Answer 1

Add this to system.web section of your web.config:

<httpRuntime requestValidationMode="2.0" />

Answer 2

Yeah .NET4 upped the security a bit. You can put it back to .NET2 mode in web.config like this:

<system.web>
  <httpRuntime requestValidationMode="2.0"/>
</system.web>