Yet another 3-4 year old, dead-end thread. Since I am getting a similar error with a 6.2 custom skin, I will post my issue here and see if we can put closure on it.

I have a custom skin which I am using for some pages, which is working fine, but when I attempt to add the same menu which is working fine in a default site skin, included in the 6.2 installation (DarkKnight - Home-Standard-Menu.ascx), I get the error.

Here is the code I added to the custom skin to include the menu:

<%@ Register TagPrefix="dnn" TagName="MENU" src="~/DesktopModules/DDRMenu/Menu.ascx" %>

<%@ Register TagPrefix="dnn" TagName="SEARCH" Src="~/Admin/Skins/Search.ascx" %>

<div id="Header">
        <div id="ContentBG">
            <div id="ControlPanelWrapper">
                <dnn:CONTROLPANEL runat="server" id="cp"  IsDockable="True" />
            </div>
            <div class="Content">
                <div id="Nav">
                    <dnn:MENU ID="MENU2" MenuStyle="DNNStandard" runat="server"></dnn:MENU>
                </div>
                <dnn:SEARCH ID="dnnSearch" runat="server" UseDropDownList="true" EnableTheming="true" Submit="Search" />
            </div>
        </div>
    </div>

Here is the error I get:

An error has occurred. DotNetNuke.Services.Exceptions.ModuleLoadException: Couldn't load menu style 'DNNStandard': System.ArgumentException: Illegal characters in path. at System.Security.Permissions.FileIOPermission.HasIllegalCharacters(String[] str) at System.Security.Permissions.FileIOPermission.AddPathList(FileIOPermissionAccess access, AccessControlActions control, String[] pathListOrig, Boolean checkForDuplicates, Boolean needFullPath, Boolean copyPathList) at System.Security.Permissions.FileIOPermission..ctor(FileIOPermissionAccess access, String path) at System.Web.InternalSecurityPermissions.PathDiscovery(String path) at System.Web.HttpRequest.MapPath(VirtualPath virtualPath, VirtualPath baseVirtualDir, Boolean allowCrossAppMapping) at System.Web.HttpRequest.MapPath(VirtualPath virtualPath) at System.Web.HttpServerUtility.MapPath(String path) at DotNetNuke.Web.DDRMenu.TemplateEngine.TemplateDefinition.FromManifest(String manifestUrl) at DotNetNuke.Web.DDRMenu.TemplateEngine.TemplateDefinition.FromName(String templateName, String manifestName) at DotNetNuke.Web.DDRMenu.MenuBase.Instantiate(String menuStyle) ---> System.ApplicationException: Couldn't load menu style 'DNNStandard': System.ArgumentException: Illegal characters in path. at System.Security.Permissions.FileIOPermission.HasIllegalCharacters(String[] str) at System.Security.Permissions.FileIOPermission.AddPathList(FileIOPermissionAccess access, AccessControlActions control, String[] pathListOrig, Boolean checkForDuplicates, Boolean needFullPath, Boolean copyPathList) at System.Security.Permissions.FileIOPermission..ctor(FileIOPermissionAccess access, String path) at System.Web.InternalSecurityPermissions.PathDiscovery(String path) at System.Web.HttpRequest.MapPath(VirtualPath virtualPath, VirtualPath baseVirtualDir, Boolean allowCrossAppMapping) at System.Web.HttpRequest.MapPath(VirtualPath virtualPath) at System.Web.HttpServerUtility.MapPath(String path) at DotNetNuke.Web.DDRMenu.TemplateEngine.TemplateDefinition.FromManifest(String manifestUrl) at DotNetNuke.Web.DDRMenu.TemplateEngine.TemplateDefinition.FromName(String templateName, String manifestName) at DotNetNuke.Web.DDRMenu.MenuBase.Instantiate(String menuStyle) at DotNetNuke.Web.DDRMenu.MenuBase.Instantiate(String menuStyle) at DotNetNuke.Web.DDRMenu.SkinObject.OnPreRender(EventArgs e) --- End of inner exception stack trace ---

Additional notes:

The identical lines of code work fine in the DarkKnight- Home-Standard-Menu.ascx skin, but fail in the custom skin.
The custom skin works fine, but fails if I add the code for the menu as shown above.
The custom skin is located in its own folder, parallel to the DarkKnight folder under the Skins folder, as shown here:
DarkKnight folder: Portals\_default\Skins\DarkKnight
Custom skin folder: Portals\_default\Skins\Website
The site default skin (Portals\_default\Skins\DarkKnight\Home-Standard-Menu.ascx), located in the DarkKnight skin folder works fine, but the custom skin (Portals\_default\Skins\Website\home.ascx) located in the Website skin folder, only fails when the code is changed to include the same menu as the one used by the DarkKnight\Home-Standard-Menu.ascx skin.
I have double checked all of the IIS and server/folder permissions as well.

Could someone please help me figure out how to include the same menu as is used by the site default skin, but in a custom skin used for a few pages.

Thank you.