Help! CS0117: xxx does not contain a definition for yyy

[Pål Andreassen]

I've got a strange problem. In a webform i have a text box of type
asp:textbox, this work fine until I change textmode to multiline. Then I
get the following error. It's not even in my file.

Compilation Error
Description: An error occurred during the compilation of a resource
required to service this request. Please review the following specific
error details and modify your source code appropriately.

Compiler Error Message: CS0117: 'System.Web.UI.WebControls.TextBox' does
not contain a definition for 'Web'

Source Error:
Line 44: System.Collections.ArrayList dependencies;
Line 45: if ((ASP.ModifyProject_aspx.__initialized == false))
{
Line 46: ASP.ModifyProject_aspx.__stringResource =
System.Web.UI.TemplateControl.ReadStringResource(t ypeof
(ASP.ModifyProject_aspx));
Line 47: dependencies = new System.Collections.ArrayList
();
Line 48: dependencies.Add("D:\\Inetpub\\Customer
\\episerver\\Intranett\\Units\\SiteFooter.ascx");
Source File: c:\WINDOWS\Microsoft.NET\Framework\v1.1.4322\Tempo rary
ASP.NET Files\root\517130a8\d54c81b\yegxd28r.0.cs Line: 46