Telerik Forums
Reporting Forum
1 answer
48 views
Suddenly, it looks like we're having issues generating excel reports possibly when the reports reach a certain size. We updated to the latest reporting version, 20.1.26.520, it's exclusively excel and of the old XLS format.

System.ArgumentException: Destination array was not long enough. Check destIndex and length, and the array's lower bounds.
   at void Array.Copy(Array sourceArray, int sourceIndex, Array destinationArray, int destinationIndex, int length, bool reliable)
   at void Array.CopyTo(Array array, int index)
   at INSTINF[] Telerik.Reporting.Excel97.SST.WriteRecordAndGetOffsets(Stream stream, uint sSTAddress)
   at void Telerik.Reporting.Excel97.Workbook.CreateSSTandEXTSSTRecords(Stream stream)
   at void Telerik.Reporting.Excel97.Workbook.WriteWorkBookRecords(Stream stream, ICollection<long> boundSheetAddresses)
   at void Telerik.Reporting.Excel97.Workbook.Save(Stream stream)
   at bool Telerik.Reporting.ExcelRendering.Excel97.ExcelReport.Telerik.Reporting.Processing.IRenderingExtension.Render(Report report, Hashtable renderingContext, Hashtable deviceInfo, CreateStream createStreamCallback, EvaluateHeaderFooterExpressions evalHeaderFooterCallback)
   at bool Telerik.Reporting.Processing.ReportProcessor.RenderCore(ExtensionInfo extensionInfo, IList<Report> processingReports, Hashtable deviceInfo, IRenderingContext renderingContext, CreateStream createStreamCallback)
   at bool Telerik.Reporting.Processing.ReportProcessor.ProcessAndRender(string format, ReportSource reportSource, Hashtable deviceInfo, IRenderingContext renderingContext, CreateStream createStreamCallback)
   at bool Telerik.Reporting.Processing.ReportProcessor.ProcessAndRenderStateless(string format, ReportSource reportSource, Hashtable deviceInfo, IRenderingContext renderingContext, CreateStream createStreamCallback)
   at RenderingResult Telerik.Reporting.Processing.ReportProcessor.RenderReport(string format, ReportSource reportSource, Hashtable deviceInfo, CancellationToken cancellationToken)+(SingleStreamManager sm) => { }
   at RenderingResult Telerik.Reporting.Processing.ReportProcessor.RenderReportSafe(Func<SingleStreamManager, bool> renderCallback, string format, IRenderingContext renderingContext)
   at RenderingResult Telerik.Reporting.Processing.ReportProcessor.RenderReport(string format, ReportSource reportSource, Hashtable deviceInfo, CancellationToken cancellationToken) x 2
   at void CabMD.TaskRunner.ReportTasks.GeneratedReportTask(Task theTask, PerformContext context) in D:/Projects/CabMD/Source/CabMD.TaskRunner/ReportTasks.cs:line 431
Dimitar
Telerik team
 answered on 11 Jun 2026
1 answer
71 views

Hello, I have a report that shows Barcodes for persons. In my development environment (Win11, .NET10), where I have installed the Report Designer for .NET10, it works perfectly (Barcode_Working_Dev.png).

When I deploy it in the production server where Telerik Report server is installed and run the report I get the underlying barcode number and not the barcode (Barcode_NotWorking_Server.png).

I am using Code39AzaleaNarrow3 Regular font (which is shown in the Font Property of the TextBox in the report).

I downloaded the Code39Azalea font from their website and installed on the server; however the issue still persists. Can you please let me know what should be done?

Thank you,

Nitin.

Dimitar
Telerik team
 answered on 27 May 2026
0 answers
68 views

Hello,

I want to ask regarding telerik web report designer, i have a TRDP that i design using Stand Alone Designer, when i upload it to Web Report Designer, the report not rendered, it throw error (only this TRDP that throwing this error):

webReportDesigner:9 Uncaught TypeError: Cannot read properties of unefined (reading 'BrowsablePropertyWrappers')
    at C.updateEditor (webReportDesigner:9:422587)
    at C.layoutChanged (webReportDesigner:9:421285)
    at HTMLInputElement.<anonymous> (webReportDesigner:9:825924)
    at HTMLDivElement.dispatch (jquery.min.js:2:40035)
    at HTMLDivElement.<anonymous> (jquery.min.js:2:38006)

The report not 'Design' mode is not rendered, but it can be 'Preview'-ed
Attached is the trdp that throwing that error.

I use telerik reporting 19.1.25.521.

Mozart
Top achievements
Rank 1
Iron
Veteran
 asked on 20 May 2026
1 answer
92 views
I have a class representing a SQL Server stored procedure output. The SP returns two datasets. I have a C# method that takes in parameters and runs the SP. It returns a ValueTuple (2 Lists - 1 each for the SP returned dataset). I tried to assign this method as the data source to an ObjectDatasource in the report (using standalone Report Designer); however I get an unexpected error (screenshot attached). Probably, it doesn't support a ValueTuple since if I connect to the class itself then it connects. If this is the case, what is the workaround?
Petar
Telerik team
 answered on 19 May 2026
1 answer
103 views

Hello,

Inherited an older application that used version "16.2.22.914"

When I follow the upgrading wizard to go to "19.1.25.521" it removes the button to export reports:

Old view:

New view:

 

Not sure if the new versions needed some additional packages added to bring this functionality in.

 

But any help or advice would be extremely appreciated!

Ivet
Telerik team
 answered on 04 May 2026
1 answer
72 views

Hi Telerik Support Team,

We are currently using Telerik Reporting in our application and are exploring the possibility of providing a chatbot-like experience to our end users for interacting with report data.

Our goal is to allow users to ask natural language questions such as:

  • “Show top 5 schemes by return”
  • “What is the XIRR of debt funds?”
  • “Why did performance drop last month?”

and receive intelligent, context-aware responses based on the underlying report data.

Our intent is to build a controlled and secure chatbot layer that interprets user queries, maps them to report parameters or datasets, and uses Telerik Reporting as the source of truth.

Any guidance, documentation references, or recommended approaches from your side would be very helpful.

Petar
Telerik team
 answered on 30 Apr 2026
1 answer
113 views

Hi everyone,

I’m currently integrating the Telerik Web Report Designer into an ASP.NET Core application and ran into an issue when trying to preview reports.

Setup:

  • Telerik Reporting Version: 2025 Q1
  • .NET Version: .NET 8
  • Integration method: manual DLL references (no NuGet packages)
  • Hosting: ASP.NET Core (Kestrel)

Problem:
The Web Report Designer itself loads correctly. I am able to browse reports, open .trdp files and modify them without any issues. However, when I try to preview a report, I consistently get the following error:

“HTML5Interactive rendering format is not available.”

Any ideas?

Ivet
Telerik team
 answered on 17 Apr 2026
1 answer
73 views

We have been running in a little bit of an issue. We have tried adding a binding to the report itself for culture to be linked to parameter but it wont change the culture of the report. We can set the binding on individual text boxes and it works fine. The other issue is from what we have found is that the culture of the report is supposed to be defaulted to the what the locale is for the computer that is running the report and we have a few international customers that are reporting that is not working.

Telerik Reporting Report Globalization - Telerik Reporting

Petar
Telerik team
 answered on 14 Apr 2026
1 answer
135 views

When I launch the Telerik Report Designer i now get the the error below, also pictured in the attachment. I was able to launch and use the application once before, but now only get this error.

"An error has occurred while merging the resource dictionaries. Make sure that no assemblies with Telerik Controls for WPF reside in the same directory as the application executable.

Error of type 'Telerik.ReportDesigner.Core.AppResourceMergeException' was thrown."

 

This seems to be the same issue mentioned here in another question on this forum.

Below is the folder with the exe files for the application. I have tried restarting the computer, reinstalling the application, and repairing the application. None of these have fixed the issue.

 

Todor
Telerik team
 answered on 26 Mar 2026
1 answer
112 views

I don't know exactly on which version when this functionality stop working but Telerik Report Viewer (HTML5) doesn't longer call /formats endpoint to get available formats on viewer initialization.

One workaround (or so) that we have found was to enable send email option to true (sendEmail: { enabled: true }) but this breaks our app as no email sending is required by our app users.

 

This is directly reproducible with build in CSharp.NetFramework.Html5IntegrationDemo and Telerik Report version 20.0.26.211 by changing

sendEmail: { enabled: true } on html js code.

 

Please advise.

Todor
Telerik team
 answered on 17 Mar 2026
Top users last month
Tien
Top achievements
Rank 1
Iron
Krasimir
Top achievements
Rank 3
Bronze
Iron
Iron
Cedar
Top achievements
Rank 1
Iron
Emil
Top achievements
Rank 1
Iron
Kyle Watson
Top achievements
Rank 1
Iron
Want to show your ninja superpower to fellow developers?
Want to show your ninja superpower to fellow developers?