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As mentioned in this RadPdfProcessing fonts documentation article
all fonts that are not from the standard 14 fonts
should be embedded in the PDF file. Due to Silverlight limitations we cannot access the system font files and cannot embed them by default in Silverlight. This causes the issue with the missing umlaut letters.
In order to workaround this issue there are two options:
I am attaching a demo PDF file that contains correctly exported umlaut letters. This PDF file is exported by slightly modifying the worksheet content in the RadSpreadProcessing SDK example
I hope this is helpful. If you have any other questions or concerns please do not hesitate to contact us again.
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