Hi Christoph,
We regret for the inconvenience caused.
Please remove the reference to Syncfusion.Pdf,Web.dll. Both Pdf.Base and Pdf.Web contain the same classes, but Pdf.Web has some changes to be able to deploy in partial trust environments. Currently, we don't provide PdfTrueTypeFont support in Pdf.Web. Could you please do find the our online documentation for more information about Partial Trust Scenarios and let me know if you need any further assistance?
http://help.syncfusion.com/ug_73/pdf/InstallationAndDeployment.htmlRegards,
Suba