Converting the attached PDF to HTML using GroupDocs.Viewer 21.10 results in a completely unreadable output.
PDF upside down.zip (200.9 KB)
image.png (25.5 KB)
This problem might occur for all 180° rotated PDF files, but at least with the two attached samples.
No special conversion code was needed to trigger the problem.
using (var viewer = new Viewer(documentPath))
{
var options = HtmlViewOptions.ForEmbeddedResources("output_viewer{0}.html");
viewer.View(options);
}