The control type 'System.Web.UI.WebControls.RegularExpressionValidator' is not allowed on this page. The type System.Web.UI.WebControls.RegularExpressionValidator code example

Example: The control type 'System.Web.UI.WebControls.RegularExpressionValidator' is not allowed on this page. The type System.Web.UI.WebControls.RegularExpressionValidator

add this safe control to your web.config

<SafeControl Assembly="'System.Web.UI.WebControls.RegularExpressionValidator', Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" Namespace="System.Web"  TypeName="*" Safe="True" AllowRemoteDesigner="True"/>