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Problem while rendering a PDF file (Groupdocs.Viewer for .NET)

i’m using groudpocs viewer for .NET (latest version) and i’m getting a problem trying to render a family of pdf files. They render as a white page and doesn’t show the content. You can compare the results between the output of the library and acrobat reader.
This is the init of the viewer widget:

        fileDisplayName: filename,
        zoomToFitWidth: true,
        locale: "it-IT",
        showFolderBrowser: false,
        showHeader: false,
        showThumbnails: true,
        useInnerThumbnails: true,
        useHtmlThumbnails: false,
        width: 650,
        height: 900,
        useVirtualScrolling: true,
        downloadPdfFile: false,
        showSearch: true,
        usePdfPrinting: true,
        enableStandardErrorHandling: false,
        preloadPagesCount: 2,
        supportPageRotation: true,
        viewerStyle: viewerSyle.OnePageInRow,
        useHtmlBasedEngine: true,
        quality: 100

Moreover, the time of the rendering is very slow with pdf files with more than 40-50 pages.

Can you try to reply this at your side? Many thanks,


7ed5d8a9-ef5d-435a-a97e-f31930c8b5be.pdf (2.2 KB)


Thanks for using GroupDocs.Viewer for .NET.

We are able to reproduce this issue at our end. It has been logged into our Issue Tracking System (with ID: VIEWERNET-1415) for further investigations. In case of any updates, we’ll inform you here.

The document rendering time depends on multiple factors such as the number of pages, document’s content which can include text, images, tables; the amount of resources that application can use; server loading and so on. However, to increase the performance and reduce the document rendering time the API provides cache feature. When GroupDocs.Viewer cache is enabled (ViewerConfig.UseCache = true), it consumes more resources and time when you render the document for the first time. When you render the same document for the second time, the API extracts data from the cache and rendering time reduces considerably.


We are delighted to inform you that your reported issue, logged as VIEWERNET-1415, has been fixed. The fix will be included in the version 17.12 of GroupDocs.Viewer for .NET. When the release will be onboard, we’ll notify you here.


The issue you have found earlier (filed as VIEWERNET-1415) has been fixed in this update.