Hi everybody, I hope that somebody can help me here.

I followed the instructions from http://devnet.kentico.com/docs/devguide/creating_an_alternative_form.htm how to create one Alternative form and use it in BizForms.

After selection of Alternative form in BizForms I get following error:

[Error loading the WebPart 'BizForm']
Unknown server tag 'cms:BizForm'.


I checked the control source code and here is what I found:

<%@ Control Language="C#" AutoEventWireup="true" CodeFile="~/CMSWebParts/BizForms/bizform.ascx.cs" Inherits="CMSWebParts_BizForms_bizform" %>

<cms:BizForm ID="viewBiz" runat="server" IsLiveSite="true" />


I was upgrading to Kentico 4.0 from 3.1 version, but during upgrade there were no errors. How should I fix this?

The same thing happens when I try to use Custom Registration Form (only with tag cms:DataForm).

Thank You for Your help.