Hello Mike Dennis,
- I am afraid that RadComboBox Templates are not supported when you use Load On Demand via WebService - that is why we do not have an example for this.
Let me explain you how Templates work - Templated Items' HTML is built at the server before it is finally rendered. This is required because the Template definition is available only at the server and Items are built using this definition.
- The reason for the error that you receive is the Request Validation that ASP.NET performs.
, is a feature of ASP.NET that prevents the server from accepting content containing un-encoded HTML. This feature is designed to help prevent some script-injection attacks. It is strongly recommended to HTML-Encode all input data. Please take a look at this article
the Telerik team