Text with Custom Fonts Is Rendered as Blank on mcr.microsoft.com/dotnet/aspnet:7.0-alpine

When we try to convert a presentation that has some text with a custom font, the text in the resulting PDF is rendered as blank. We use In-Memory fonts to load the corresponding custom font. Works fine on windows, but when we render in container that is based on mcr.microsoft.com/dotnet/aspnet:7.0-alpine it doesn’t work. In the attachment there is a simple code sample as well as an example docker file that we use to run the application on production.
Tests.Alpine.zip (58.8 KB)

Thank you for describing the issue.

Could you please also share your output PDF file?

Input: Presentation.7z (24.3 KB)
Output: output.7z (1.5 KB)

Thank you for the output file. Please try loading the external font before instantiating the presentation like this


instead of the following way

DocumentLevelFontSources = new FontSources
    MemoryFonts = fonts.ToArray()

We will be waiting for your results.

Here is the result: Alpine_ConvertedPDF.pdf (21.3 KB). It’s still blank.
Here is the code that we use to generate it:

using Aspose.Slides;
using Aspose.Slides.Export;

public static class PowerPointToPdf
    public static async Task Convert()
        var sourceStream = File.OpenRead(Path.Combine("Samples", "Presentation.pptx"));
        Console.WriteLine($"Loaded presentation (size: {sourceStream.Length})");
        var fontContent = await File.ReadAllBytesAsync(Path.Combine("Samples", "LimeGloryCaps.ttf"));
        Console.WriteLine($"Loaded font file (size: {fontContent.Length})");
        var fonts = new byte[][] { fontContent };
        var presentation = new Presentation(sourceStream);
        await using var outputStream = new MemoryStream();
        Console.WriteLine($"Starting conversion to PDF");
            new PdfOptions
                Compliance = PdfCompliance.PdfUa
        outputStream.Position = 0;
        Console.WriteLine($"Conversion to PDF finished");
        await File.WriteAllBytesAsync(@"Samples/ConvertedPDF.pdf", outputStream.ToArray());
        Console.WriteLine($"Saved PDF file (size: {outputStream.Length})");

On windows still works fine, here is the genaretaed output: Windows_ConvertedPDF.pdf (39.0 KB)

We have opened the following new ticket(s) in our internal issue tracking system and will deliver their fixes according to the terms mentioned in Free Support Policies.

Issue ID(s): SLIDESNET-43752

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