Converting EBook crashes on Mac and Linux

We use a common component for converting various documents to PDF.
The component runs on Windows, Mac and Linux.
Converting the attached EBook works fine on Windows but fails on Mac and Linux.

The code for converting:
Aspose.Pdf.EpubLoadOptions option = new Aspose.Pdf.EpubLoadOptions();
using (Aspose.Pdf.Document pdfDocument = new Aspose.Pdf.Document(importFile, option))
pdfDocument.Save(pdfFile);

Stack from Mac:
System.NullReferenceException: Object reference not set to an instance of an object. at #=zBLNT1q$kVkwj5brabTwrwLvaPWAKY1jJu$tllZ8=.#=zQbDdeBu23vvT
… obfuscated stuff …
at Aspose.Pdf.Document.#=z7hSlsVI=(Stream #=zyUEvkTs=, LoadOptions #=z48c_1lM=)
at Aspose.Pdf.Document…ctor(String filename, LoadOptions options)
at SSD.ATLASti.CrossPlatform.AsposeExtensions.SSDEBookToPDFConverter.ConvertToPDF(String importFile, String temp)

Stack from Linux
System.NullReferenceException: Object reference not set to an instance of an object. at Aspose.Pdf.Text.Font…ctor(#=zUl4FX_sunrTyVXVaDB8g3II= #=zSW8FB5Y=)
… obfuscated stuff …Deppen Ahoi.zip (1.8 MB)

@mausbeer

I have been able to reproduce the issue on our end. A ticket with ID PDFNET-50367 has been created in our issue tracking system to further investigate the issue on our end. This thread has been linked with the issue so that you may be notified once the issue will be fixed.