If the HTML5 Report Viewer gets hidden on renderingBegin(e, args) event and shown on renderingEnd(e, args) event, its toolbar is shown, but the contents are still invisible.

Code snippet that demonstrates the issue:

$("#reportViewer1")
    .telerik_ReportViewer({
		... initialization script goes here
        renderingBegin: function (e, args) {
           $("#reportViewer1").hide();
        },
        renderingEnd: function (e, args) {
           $("#reportViewer1").show();
        }
    });

Hello, 

I currently have a WebServiceDataSource in my report using a POST Method, a Body and a Parameter for Content-Type.

However, if I try to add a second WebServiceDataSource with a Content-Type parameter it throws an error saying that the Name already exists.

See the following screenshot for a visual reference.