Word to PDF font Incorrect

Using licensed version of Aspose.Words.NET
When converted words to pdf, it cannot show correct font type

fonts type is Frutiger Ultra

 Dim asposeDoc As New Aspose.Words.Document("d:\\beeo\\CaseAttachment\\" & "a.docx")
 Dim pso As New Aspose.Words.Saving.PdfSaveOptions()
pso.Compliance = Saving.PdfCompliance.PdfA1a
asposeDoc.Save("d:\\beeo\\CaseAttachment\\" & "b.pdf")

Any idea?

@blackcatabc The problem might occur, for example, because the fonts used in your original document are not available in the environment where document conversion is performed. To build document layout the fonts are required. If Aspose.Words cannot find the font used in the document, the font is substituted. This might lead into fonts mismatch and document layout differences. You can implement IWarningCallback to get notifications when font substitution is performed.