Last Updated: 07 May 2021 18:53 by Douglas
Float report parameter = 0 or negative whole number is returned as int and an exception is thrown in the viewer. The issue is observed only in .NET Core projects.
Last Updated: 06 May 2021 12:21 by ADMIN
If you try to add a new selector in a new or existing StyleRule in the WebReportDesigner, a new TypeSelector gets added automatically rather than letting you choose from the list of the available selectors.
Under Review
Last Updated: 05 May 2021 10:27 by Frantisek
Created by: Frantisek
Comments: 8
Type: Bug Report



I have problem with visual studio auto close when I'm working in reporting designer.

When I'm working in reporting designer and do about 5 changes, Visual studio freezes and after few monents is restarted and I loose all my work.

It is really frequented problem and I can hardly work with reporting designer.


In Windows Event Viewer I everytime find this exception that referes to problem in GetAggregateFunctions().

Application: devenv.exe
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.NullReferenceException

Server stack trace: 
   at Telerik.Reporting.Processing.AggregateFunctionHelper.GetAggregateFunctions(IServiceProvider provider)
   at Telerik.Reporting.Design.Common.ExpressionBuilder.CategoryAdapter.<GetAggregates>d__1b.MoveNext()
   at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
   at Telerik.Reporting.Design.Common.ExpressionBuilder.CategoryAdapter.FillAggregates(Category funcCategory, IServiceProvider provider)
   at Telerik.Reporting.Design.Common.ExpressionBuilder.CategoryAdapter.CreateHierarchy(IServiceProvider provider, Boolean isFieldsTreeVisible)
   at Telerik.Reporting.Design.Common.ExpressionBuilder.ExpressionBuilderDialog.LoadCategories(IServiceProvider provider)
   at System.Runtime.Remoting.Messaging.StackBuilderSink._PrivateProcessMessage(IntPtr md, Object[] args, Object server, Object[]& outArgs)
   at System.Runtime.Remoting.Messaging.StackBuilderSink.AsyncProcessMessage(IMessage msg, IMessageSink replySink)
   at System.Runtime.Remoting.Proxies.RealProxy.EndInvokeHelper(System.Runtime.Remoting.Messaging.Message, Boolean)
   at System.Runtime.Remoting.Proxies.RemotingProxy.Invoke(System.Object, System.Runtime.Remoting.Proxies.MessageData ByRef)
   at Telerik.Reporting.Design.Common.ExpressionBuilder.ExpressionBuilderDialog+LoadCategoriesDelegate.EndInvoke(System.IAsyncResult)
   at Telerik.Reporting.Design.Common.ExpressionBuilder.ExpressionBuilderDialog.OnLoadCategoriesComplete(System.IAsyncResult)
   at System.Runtime.Remoting.Messaging.AsyncResult.SyncProcessMessage(System.Runtime.Remoting.Messaging.IMessage)
   at System.Runtime.Remoting.Messaging.StackBuilderSink.AsyncProcessMessage(System.Runtime.Remoting.Messaging.IMessage, System.Runtime.Remoting.Messaging.IMessageSink)
   at System.Runtime.Remoting.Proxies.AgileAsyncWorkerItem.DoAsyncCall()
   at System.Runtime.Remoting.Proxies.AgileAsyncWorkerItem.ThreadPoolCallBack(System.Object)
   at System.Threading.QueueUserWorkItemCallback.WaitCallback_Context(System.Object)
   at System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
   at System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
   at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
   at System.Threading.ThreadPoolWorkQueue.Dispatch()
   at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback()

Last Updated: 04 May 2021 04:01 by Tursunkhuja
When using a report parameter of type Float, and there is no value for decimal places, or it is 0, it appears as if the parameter value passed to the runtime is converted to an integer value, and an "Invalid value for parameter <paramName>" is logged. 
Last Updated: 03 May 2021 06:37 by ADMIN
Navigating through the report with the document map does not navigate to the right item(position) on high zoom level
In Development
Last Updated: 03 May 2021 06:13 by ADMIN
When creating a chart, in the values field, you cannot change the function being used. The dropdown list contains only undefined values.
Last Updated: 29 Apr 2021 11:25 by ADMIN

When a textbox cannot fit on the current page and its Style.VerticalAlign is not set to Top, the textbox is pushed to the next page, although its KeepTogether property is set to false and its Value is null or empty.

This scenario usually happens when a textbox in a table grows vertically because the table contents also grow - it might be another nested table or any other data item. The solution is to either set the visibility of the textbox to false or set its Style.VerticalAlign to Top.

Last Updated: 28 Apr 2021 15:11 by ADMIN
 After the upgrade on telerik-angular-report-viewer to ^12.21.120 from  ^10.20.513, the viewer doesn't make requests to the service. The reports controller uses authentication, which might be related to the issue. The attached file consists of 2 projects- 1 with the old version that is working and the new version that does not work.
Last Updated: 28 Apr 2021 14:08 by ADMIN

Not sure if you are aware of this but the new property SkipBlankPages in 2021/R1 will result in a corrupt (unopenable) PDF/XLS if the report contains no data.

The output used to be a blank report.

This behaviour is fixed by setting the Value to 'False' but this now requires the developer to remember to set this value on each new report. Perhaps the default should have stayed as 'False' and those who wish to remove blank pages could set it to true.

We are aware the property is set to true by default.

We have now had to modify (and subsequently retest) > 100 reports.

The generator should probably not create a 'corrupt' file in these cases.

Kind regards

Last Updated: 28 Apr 2021 12:07 by ADMIN
My report has 4 levels of nested subreports. Each child subreport receives its data from the parent with Binding to a data field from the parent report data source. This works correctly with versions and but doesn't show the correct data with version For details see the forum post Invalid subreport data when updating to latest telerik reporting version.
In Development
Last Updated: 26 Apr 2021 11:29 by ADMIN

There are two issues I observed with the Web Designer:

1.If you edit any Report Parameter Value from Designer it will convert to [object Object]

2. And clicking the ellipses (...) to edit the value, opens and closes the modal dialog sometimes.

Last Updated: 26 Apr 2021 06:40 by ADMIN
1. A custom report template is checked for getting the data source information needed
2. A new empty Telerik report is created
3. The report is client-side filled with those predefined data sources using the Telerik Javascript Shell (EditorCommand.NewItem for creating them and SetPropertyValue for filling in the details).

This approach has been working well for me until getting updated to the R1 2021 SP1 release (, or the following versions, which are now unable to show the datasources fields in the explorer at first. However, manually adding a new component into the canvas makes the datasource tree to be updated then.
Last Updated: 26 Apr 2021 06:37 by ADMIN


I am receiving the TypeError: $kendoHtmlEncode error in an Angular Report Viewer with the SystemJS. I am also using a .NET Framework (4.6.2) WebApi based Reporting REST Service. See the following screenshot of the error. 

Additionally, the Report Viewer UI is loading until the error is thrown and the report never loads as shown in the following screenshot.

Note that I am also using a separate process for running each project.

For additional reference, I have attached a sample that reproduces the error. See the following steps to run the sample locally.

  1. Open the 1515808.sln file in Visual Studio.
  2. Restore the NuGet Packages.
  3. Run the included WebApi project.
  4. Open the src/ClientApp folder in a command window.
  5. Run npm install from the CLI.
  6. Execute npm run serve from the CLI.

Please let me know if you need any additional information. Thank you.

Last Updated: 23 Apr 2021 15:03 by ADMIN

If you select valid values for a multi-value parameter and then deselect them manually in List_View, the last rendered report remains and there is no warning for invalid parameter values and the Preview button is not disabled. The problem occurs only in List_View for the multivalue parameter editors.

If you deselect the values with 'clear selection' the proper warning gets displayed.

In Development
Last Updated: 23 Apr 2021 07:22 by ADMIN

Internal Server Error. The operation was canceled is thrown in the viewert when the SVG contains 

<?xml version="1.0" encoding="UTF-8"?>

Last Updated: 18 Apr 2021 13:51 by ADMIN
When you exporting the template from a report on the report server, it gives the "Template build failed" error message.
Last Updated: 16 Apr 2021 11:36 by ADMIN

We pass Report Parameters as Strings and later convert them to Floats in the Report. This works fine on our production systems in Switzerland but fails on dev machines that use different system locales.

Last Updated: 15 Apr 2021 07:25 by ADMIN
When you export a report from VBA, the image is missing in the PDF file. It is important that the problem is reproducible only on machines that Telerik Reporting has never been installed. With the same code, when exporting from VS, the report is correctly exported. The attached PDF files represent the outcome from both exports.
Last Updated: 14 Apr 2021 09:05 by ADMIN
Created by: Todd
Comments: 1
Type: Bug Report


I create an ASP.NET Web Application - Empty. I add to it a Telerik HTML Report Viewer page. The wizard creates a new REST service with a sample report. Inside the Html5ReportViewer.html file is the line

<!--If Kendo is used it should be added before the report viewer.-->

 <script src="/api/reports/resources/js/telerikReportViewer-"></script>


with a trailing / in the src attribute. This works perfectly.


I have a ASP.NET Webforms website that displays reports from the Reporting web application.  Pages that display a report also have this script tag. However, any time there is an update for the Reporting toolkit, if I use the Reporting Upgrade Wizard, (Visual Studio 2019 "Extensions" menu -> Telerik -> Reporting -> Upgrade Wizard) the script tags get updated with the latest version, but the trailing / in the src attribute is no longer there and the page breaks because the Javascript library is not loaded. Adding in the / fixes the problem.  Is this intended behavior or a bug in the upgrade wizard?


Last Updated: 14 Apr 2021 08:58 by ADMIN

1. Open report in the EUD.
2. Click "Export Template".
3. Select the open report and click "Next" and "Finish" to complete the wizard. The newly created template is visible in the User Templates as expected.
4. Click "Export Template".
5. Select the open report and click "Next" and "Finish" to complete the wizard. Warning is shown that this template exists. https://gyazo.com/91cac78640a551411c67df4abaecce78
6. Click "Yes" so that the template is replaced.

Expected: Template is recreated.
Observed: Error "Template build failed" https://gyazo.com/6ea75f7fba0674679a3c4df8ba73c307.
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