We are experiencing a critical issue with the RadPdfViewer control after upgrading to version 2024.4.1113. Previously, we were using version 2017.X and everything worked correctly.

After the upgrade, when some users try to load PDFs in the viewer, the documents are either:

• Completely blank,

• Filled with black squares,

• Or displayed in a distorted/incorrect format.

The issue is inconsistent — the same PDF files that display incorrectly for some users render just fine for others. All users are accessing the same application via a Windows RDS (Remote Desktop Services) environment.

What makes this even more confusing is that:

• The issue only affects certain users on the RDS server.

• The exact same PDF can be opened successfully by one user but fails for another.

• The application and environment are otherwise identical between users.

We’ve confirmed that the issue started only after upgrading the Telerik controls to the latest version.

Can you please assist us in identifying the cause and provide any recommendations or patches that could resolve this issue?

Environment:

• Telerik UI for WinForms v2024.4.1113

• Windows Server with RDS

• .NET Framework version: 4.7.1

• Application in VB.NET (WinForms)

Please let us know if any logs, test files, or further information is required.

Best regards,
André Borges,
F3M

Hi,

I've been struggling to work out how to export the current pdf page as shown in the pdfViewer after it has been rotated using controls in the pdfViewerNavigator. I'm trying to save the image in png format but it seems to export the page in the original orientation ignoring the applied rotation.  

Also whilst searching the forum for a solution, I came across the code

but  it appears that PageNo no longer exists in 2020.3.1020.

Currently i'm using

which exports the first page as a png, which works, I just need to save the currently selected page that may or may not have been rotated.

Is this possible, if so how ?

¡Hi everyone! I have this issue loading a pdf with the RadPdfViewer.
On the RadPdfViewer DataError event i got an InvalidOperationException with only the "Stack empty" messsage,

This is the stacktrace of the exception thown by the PdfExceptionEventArgs

   at System.ThrowHelper.ThrowInvalidOperationException(ExceptionResource resource)
   at System.Collections.Generic.Stack`1.Pop()
   at Telerik.Windows.Pdf.Documents.Fixed.FormatProviders.Old.Pdf.DocumentModel.PdfContext.RestoreGraphicState()
   at Telerik.Windows.Pdf.Documents.Fixed.FormatProviders.Old.Pdf.PdfReader.Parsers.ContentStreamParser.InvokeGeneralGraphicsStateOperator(String op, Object[] pars)
   at Telerik.Windows.Pdf.Documents.Fixed.FormatProviders.Old.Pdf.PdfReader.Parsers.ContentStreamParser.InvokeOperator(String op, Object[] pars)

Can you please tell me what could be the possible reason of this issue ? Thanks

PS. The file is on the zip attached

I have this code, and I just want to export all pages or a specific page from the loaded PDF in the RadPdfViewer, without saving the file to the computer.

The function RadPdfViewer.ExportPage returns a Bitmap, but when I assign the result of this function to a new variable of type Bitmap, an error occurs.

'1º Option - Work
            For i As Integer = 1 To RadPdfViewer1.Document.Pages.Count
                Dim guid As Guid = Guid.NewGuid

                RadPdfViewer1.ExportPage(i, "C:\temp\" & guid.ToString() & ".pdf", 1, True, ImageFormat.Png)

                Dim bitmap As Bitmap = New Bitmap("C:\temp\" & guid.ToString() & ".pdf")

                Dim reader As BarcodeReader = New BarcodeReader With {
                        .AutoRotate = True,
                        .TryInverted = True
                        }

                Dim result As Result = reader.Decode(bitmap)

                If result Is Nothing Then Continue For

                Dim decoded As String = result.ToString().Trim()

                If decoded Is Nothing Then Continue For

                If decoded <> TextBox1.Text Then TextBox1.Text = TextBox1.Text & vbNewLine & vbNewLine & decoded

                bitmap.Dispose()
                My.Computer.FileSystem.DeleteFile("C:\temp\" & guid.ToString() & ".pdf")
            Next

            '2 Option - Dont Work
            Dim bitmap As Bitmap = RadPdfViewer1.ExportPage(1, 1, False, ImageFormat.Png)

            '3º Option - Dont Work
            For Each bitmap As Bitmap In RadPdfViewer1.ExportPages(1, False, ImageFormat.Bmp)
                Dim reader As BarcodeReader = New BarcodeReader With {
                        .AutoRotate = True,
                        .TryInverted = True
                        }

                Dim result As Result = reader.Decode(bitmap)

                If result Is Nothing Then Continue For

                Dim decoded As String = result.ToString().Trim()

                If decoded Is Nothing Then Continue For

                If decoded <> TextBox1.Text Then TextBox1.Text = TextBox1.Text & vbNewLine & vbNewLine & decoded
            Next

Hi, I'm using a RadPdfViewer to show a Pdf.

If the pdf is signed the signatures panel is showed, but the signature is always showed as not valid, even if it is valid.
The error is that the "The signer's identity isunknown".

I tried also to call the SignatureField.Signature.Validate() method and it throws an exception like this:

No signature validation handler was found for the subfilter: ETSI.CAdES.detached

Any suggestion?

Thanks.

We have incomming PDF documents that have been annotated/marked up/stamped (we beleive using Adobe). When you view or print from Telerik the "annotations" are missing or wrongly formated. 

Chrome and Edge both display the PDF correctly.

Are there any properties or techniques I can use to get Telerik PDF to include the annotations ?

Attached are the original PDF "PDFMarkUp.pdf" and the PDF as printed by Telerik "PDFMarkUpOUT.pdf" (Replicates the Telerik View )

How to convert PDF pages to images in .NET Framework app? I've scoured the site, and it seems you recommend something like this:

RadPdfViewer pdfViewer = new RadPdfViewer();

pdfViewer.DocumentLoaded += (sender, e) =>
{
	if (sender is RadPdfViewerElement pdfViewerElement)
	{
		for (int i = 1; i <= pdfViewerElement.Document.Pages.Count; i++)
		{
			Image pageImage = pdfViewerElement.ExportPage(i, 1, true, ImageFormat.Jpeg);

			// Use pageImage
		}
	}
};

pdfViewer.LoadDocument(pdfPath);
pdfViewer.LoadElementTree();
Application.DoEvents();

Is this really the best way for .NET Framework apps? There is an example that uses PdfProcessing instead of PdfViewer, but requires the assembly Telerik.Documents.Fixed.FormatProviders.Image.Skia, which I don't have available in my Visual Studio with latest update of Telerik UI for WinForms 2024.3.806.462. Nor is it available on nuget, or I don't know how to find it.

I'm using Visualstudio2022 Dark theme on my program. When I load a fillable PDF to the PDF viewer, the back color of the form fields turns to black when I click on them. 

I tried changing the annotations color and the text color of the form fields, but nothing works.

How do I change the back color from black to white of the form fields on a fillable PDF? 

Hi, I'm using a RadPdfViewer to show a document, and a RadPdfViewerNavigator associated with him.

I have 2 questions:

1) I've noticed that even if the pdf document is not loaded in the RadPdfViewer control, all buttons in the RadPdfViewerNavigator are enbaled, then the user can click on some button and I tthink this is not correct (further, the application can crash if he clicks for example, on the rotate button). Is there a way to tells that to the RadPdfViewerNavigator to enable/disable buttons in base of loaded document, or I need to do it programmatically?
2) The print preview form is very well and powerful, but I've noticed that it is very slow to move from a page to another... It can be a problem on my own, or it is by design?

Thank you for any assistance.