When few fillable pdf's are unable to flattern by using the below code in .net mvc 4.5.1 with spire 8.2.2 licensed version.
PdfDocument doc = new PdfDocument(PDFPath);
if (doc.Form != null)
{
_logger.Info("fillable pdf");
doc.Form.IsFlatten = true;
}
the sample fillable pdf is attached. Need to convert it as flattern pdf and need to compress its size too.