When you try to send the report through the SendMailMessage functionality but an exception is thrown, the report will disappear. If you click on Refresh and try again with fake data, the exception will be thrown but the report will remain. If you prefer to refresh it automatically, you can use the error event:

var viewer = $("#reportViewer1")
.telerik_ReportViewer({
    serviceUrl: "api/reports/",
    reportSource: {
        report: "Report Catalog.trdp",
    },
    error: function (e, args) {
        console.log("This event handler will be called after a page of the report is ready.");
        console.log("The error message is: " + args);
        viewer.refreshReport();
    },
    viewMode: telerikReportViewer.ViewModes.INTERACTIVE,
    scaleMode: telerikReportViewer.ScaleModes.SPECIFIC,
    scale: 1.0,
    enableAccessibility: false,
    sendEmail: { enabled: true }
}).data("telerik_ReportViewer");

The following exception occurs when you attempt to add a Html5 Report Viewer from the VS item template in a project that already contains a CLR report:

"Error: Fail to add project reference System.Runtime.InteropServices.COMException (0x80004005): Adding 'WebApplication2' as a project-to-project reference would cause this project to reference itself. at VSLangProj.References.AddProject(Project pProject) at Telerik.Reporting.Vs.Common.ProjectManager.TryAddProjectReference(Project projectToReference)"

The viewer is still added successfully and displays the report.

Steps to reproduce:

1. Create a Blazor application;

2. Add Teleri.Reporting NuGet package;

3. Add Telerik.WebReportDesigner.Services Nuget package -> some of the app dependencies are broken.

Solution:

Refer the .NET Standard DLLs from C:\Program Files (x86)\Progress\Telerik Reporting <Version>\Bin\netstandard2.0.

As a full time developer I'm constantly switching between open documents.

It would be very nice if the Report Designer would support the standard Ctrl+Tab keyboard shortcut for switching between open tabs.