I've googled this, checked the web.config and a host of other things. (App Pool .net versions and the like)

 Has anyone ever solved this?  The usual of making sure the web.config server extensions has been checked, is right.  App Pool .Net version is right, etc.  But I can't build the website solution without getting this error.

All I'm really doing is extending Security Roles so as to make non-admin users of a certain flavor able to add roles at the click of a button.  I can create this, get it working, install it on the dev server site and take it from there but I'd really like to solve this pesky dang error.

Thanks!

Sure.  I'm also getting a host of errors in code that contains Lambda expressions and I'm not sure of what's doing that.  It cleared up last night with the error below being the only one to show up.

Let me know what else you need.

The error is:  Error    1    Unknown server tag 'asp:UpdatePanel'.    C:\DNNSites\...\wwwroot\admin\ControlPanel\AddModule.ascx    108    

HTML is:

<asp:UpdatePanel ID="UpdateAddModule" runat="server" ChildrenAsTriggers="true">
    <contenttemplate>
        <div class="dnnCPAddModule">
            <h5><asp:Label runat="server" ResourceKey="AddModule" /></h5>            
            <asp:RadioButton ID="AddNewModule" runat="server" ResourceKey="AddNew" GroupName="AddModule" Checked="true" AutoPostBack="true" />           
            <asp:RadioButton ID="AddExistingModule" runat="server" ResourceKey="AddExisting" GroupName="AddModule" AutoPostBack="true" />            
            <asp:HyperLink ID="hlMoreExtensions" runat="server" CssClass="dnnPrimaryAction" Visible="false" />
        </div>
        <div class="dnnCPModSelection dnnFormItem">
            <h5><asp:Label ID="Label1" runat="server" ResourceKey="SelectModule" /></h5>
            <asp:Panel ID="SiteListPanel" runat="server" Visible="True" CssClass="dnnClear">
               <asp:Label ID="SiteLbl" runat="server" ResourceKey="Site" AssociatedControlID="SiteList"></asp:Label>
               <dnn:DnnComboBox ID="SiteList" runat="server" AutoPostBack="true" />
            </asp:Panel>
            <asp:Panel ID="CategoryListPanel" runat="server" Visible="false" CssClass="dnnClear">
                <asp:Label ID="CategoryListLbl" runat="server" ResourceKey="Category" AssociatedControlID="CategoryList" />
                <dnn:DnnComboBox ID="CategoryList" runat="server" AutoPostBack="true" DataTextField="Name" DataValueField="Name" />
            </asp:Panel>
            <asp:Panel ID="PageListPanel" runat="server" Visible="false" CssClass="dnnClear">
                <asp:Label ID="PageListLbl" runat="server" ResourceKey="Page" AssociatedControlID="PageLst" />
                <dnn:DnnComboBox ID="PageLst" runat="server" AutoPostBack="true" />
            </asp:Panel>
            <div class="dnnClear">
                <asp:Label ID="ModuleLstLbl" runat="server" ResourceKey="Module" AssociatedControlID="ModuleLst" />
                <dnn:DnnModuleComboBox ID="ModuleLst" runat="server" />
            </div>
            <asp:Panel ID="TitlePanel" runat="server" Visible="true" CssClass="dnnClear">
                <asp:Label ID="TitleLbl" runat="server" ResourceKey="Title" AssociatedControlID="Title" />
                <asp:TextBox ID="Title" runat="server" />
            </asp:Panel>
            <div class="dnnClear">
                <asp:Label ID="VisibilityLstLbl" runat="server" ResourceKey="Visibility" AssociatedControlID="VisibilityLst" />
                <dnn:DnnComboBox ID="VisibilityLst" runat="server" />
            </div>
        </div>
        <div class="dnnCPModLocation dnnFormItem">
            <h5><asp:Label ID="Label2" runat="server" ResourceKey="LocateModule" /></h5>
            <div class="dnnClear">
                <asp:Label ID="PaneLstLbl" runat="server" ResourceKey="Pane" AssociatedControlID="PaneLst" />
                <dnn:DnnComboBox ID="PaneLst" runat="server" AutoPostBack="true" />
            </div>
            <div class="dnnClear">
                <asp:Label ID="PositionLstLbl" runat="server" ResourceKey="Insert" AssociatedControlID="PositionLst" />
                <dnn:DnnComboBox ID="PositionLst" runat="server" AutoPostBack="true" />
            </div>
            <div class="dnnClear">
                <asp:Label ID="PaneModulesLstLbl" runat="server" ResourceKey="Module" AssociatedControlID="PaneModulesLst" />
                <dnn:DnnComboBox ID="PaneModulesLst" runat="server" />
            </div>
            <div class="dnnFormCheckbox"><asp:CheckBox ID="chkCopyModule" runat="server" /></div>
        </div>
        <a href=" void(0)" class="dnnPrimaryAction" id="cmdAddModule_Fake"><%= GetString("AddModule.Text") %></a>
        <asp:LinkButton ID="cmdAddModule" runat="server" ResourceKey="AddModule" CssClass="Hidden"  />
    </contenttemplate>
</asp:UpdatePanel>

Mark,

 Forgive me, I didn't distinguish there are 2 different things happening here.  Also I can't figure out why this line I copied from VS 2010 Error Window mysteriously shows up once I submit but isn't viewable in Edit so I can delete it:
</dotnetnuke.entities.users.userroleinfo></dotnetnuke.entities.users.userroleinfo>  So where you see this in the submitted post it's because I can't view it to remove it.  I suspect it's being interpreted as HTML and finding it's way into wherever it can fit.  Sorry for the confusion but it's a text editor issue.

1. I'm using Edit Roles and Security Roles code out of /admin/security/ to create a module.  It has a host of errors in it mainly caused by errors due to Lamda Expressions and Extension Methods.  This is not where the error mentioned above lives.
2. When I build the site I get an error in the admin/control panel/AddModule.ascx file.  This is not part of my project.  It lives in the DNN site code that ships with whatever is in the /Admin folder of Desktop Modules.
   
   The error I get when building the site is:  Error    18    Unknown server tag 'asp:UpdatePanel'.
   Since this module ships with DNN, I'm assuming any references it needs to AJAX are installed?   
   
   How I created the solution for the site, since I didn't have the full source code and the DNN solution itself was to Open Site in VS 2010, browse to the site and open it.  Create the solution, copy over any files from /Desktop Modules/Admin/ to the folder in Desktop Modules where my project lives.

Might these errors in Add Module and the Security code I'm modifying have a setup issue in common and I've overlooked it?  I've not had this ever come up with VS 2005 or VS 2008.  See below, I just opened this site by browsing to the copy of it I have locally with VS 2010 and used the Open Site dialog.

The errors I'm getting for the project I'm creating are:

1. Error    21    'System.Array' does not contain a definition for 'ToList' and no extension method 'ToList' accepting a first argument of type 'System.Array' could be found (are you missing a using directive or an assembly reference?) 
   
   
2. Error    22    'System.Collections.Generic.IList<dotnetnuke.entities.users.userroleinfo>' does not contain a definition for 'Skip' and no extension method 'Skip' accepting a first argument of type 'System.Collections.Generic.IList<dotnetnuke.entities.users.userroleinfo>' could be found (are you missing a using directive or an assembly reference?)
   
   I found an article stating these are Extension Methods but didn't find anything about how to clear them.  The DLL files that contain these interfaces/objects are in the Usings section and of course live in the /bin folder.  I'm missing what's up here.  This should be straightforward to clear so I confess there's a gap for me here.
   
   </dotnetnuke.entities.users.userroleinfo></dotnetnuke.entities.users.userroleinfo>
3. There are 5 of these errors:  Error    18    Cannot convert lambda expression to type 'System.Func<dotnetnuke.security.roles.roleinfo,bool>' because it is not a delegate type.  Here is a line of code where this is being thrown: RoleInfo role = TestableRoleController.Instance.GetRole(PortalId, r => r.RoleID == roleId);  Again, the live site runs.
   
   OK, the site runs on the live server just fine.  So someone tell me how the code could possibly build?  Again, I'm having obvious gap issues.  This should be straightforward to clear.
   </dotnetnuke.security.roles.roleinfo,bool>
4. Next there are 2 of these errors:  Error    25    The name 'UI' does not exist in the current context.  Another BS error. :)  This lives in the fully qualified namespace DotNetNuke.UI ... and so on.  The line of code is here: UI.Skins.Skin.AddModuleMessage(this, Localization.GetString("RoleRemoveError", LocalResourceFile), ModuleMessage.ModuleMessageType.RedError); and if DotNetNuke. is prefixed to UI.Skins ... the error clears.  Using DotNetNuke; is definitely in the Usings section.
   Go Figure ... :)

What setup omission might cause these errors?

 Thanks, Mark.