If the user try to upload licensed font, Content Exporter can not export it.
The problem is, that CEX doesn't show a correct error message about it.
The exception
com.lowagie.text.DocumentException: C:\Munka\CEX\cloud-content-exporter\.\tmp\87eb14d41eeeac0bd7fe0c62ece05134bbf1ee8059b6e3e701d7f4a7799506dc_DS-DIGI.TTF cannot be embedded due to licensing restrictions.
at com.lowagie.text.pdf.TrueTypeFontUnicode.<init>(Unknown Source)
at com.lowagie.text.pdf.BaseFont.createFont(Unknown Source)
at com.lowagie.text.pdf.BaseFont.createFont(Unknown Source)
at com.lowagie.text.pdf.BaseFont.createFont(Unknown Source)
at org.xhtmlrenderer.pdf.ITextFontResolver.addFont(ITextFontResolver.java:201)