The Active schema does not support the element DisplayLayout, AddNewBox, Bands etc..
I came across this issue when I tried to add an Infragistics UltraWebGrid to the ASP .Net page. Everything looks fine in the Design mode. When you switch to HTML mode, you will find a lot of squiggly linesunder DisplayLayout, BorderDetails etc saying the active schema does not support these elements
And when you try to run your asp pages, you may see the following error:
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: CS0234: The type or namespace name 'BorderDetails' does not exist in the class or namespace 'Infragistics.WebUI.Shared' (are you missing an assembly reference?)
Source Error:
<igtbl:UltraWebGrid id="UltraWebGrid1" style="Z-INDEX: 103; LEFT: 768px; POSITION: absolute; TOP: 264px"
Line 72: runat="server"
DisplayLayout RowHeightDefault="20px" Version="4.00" BorderCollapseDefault="Separate" Name="UltraWebGrid1">
It looks like Visual Studio does not recognizes the 3rdparty software and does not import the required assembly files ie Infragistics.WebUI.Shared Elements. In order to avoid this, make sure that this assembly has been added to the references and SET the CopyLocal property to true.. Run your code and you should now be able to bring up your ASP .NET page. Note that thisdoes not remove the squiggly lines in the HTML mode but it does not stop you from designing and building your app!!