We have been using an editor on a page in R1 implemented like below, but after auppgrading to R2 we get the following error on the page:
[Error: No property "MyLongStringProperty".]      

What kind of changes has been done? 

Info: I do not want the editor to fetch values from a certain page in EPiServer we only want to use yte editor and it's functionality including the ability to select images etc from EPiServer filesystem.

<EPiServer:Propertyid="myHtmlEditor"Width="650"height="350"EditMode="true"runat="server"/>

And this on cs:
overridevoid OnInit(EventArgs e)
{
base.OnInit(e);
if (!Page.ClientScript.IsClientScriptIncludeRegistered("system.js"))
{
Page.ClientScript.RegisterClientScriptInclude("system.js", ((PageBase)Page).ResolveUrlFromUI("javascript/system.js"));
Page.ClientScript.RegisterClientScriptInclude("system.aspx", ((PageBase)Page).ResolveUrlFromUI("javascript/system.aspx"));
Page.ClientScript.RegisterClientScriptInclude("episerverscriptmanager.js", ((PageBase)Page).ResolveUrlFromUtil("javascript/EPiServerScriptManager.js"));
}
PropertyXhtmlString xhtmlString = newPropertyXhtmlString();

// select chosen options or use EditorToolOption.All
xhtmlString.EditorToolOptions = EditorToolOption.All;
xhtmlString.Name = "MyLongStringProperty";
HtmlEditor.InnerProperty = xhtmlString;
}