With 1.50 beta3b I sometimes get an System.ArgumentException: An item with the same key has already been added.
Unfortunately I cannot reproduce it, it just happens randomly in production from time to time.
Here's the stacktrace hopefully you can figure something out of this small peace of information:
Code:
System.ArgumentException: An item with the same key has already been added.
at System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add)
at PdfSharp.Fonts.OpenType.GlyphTypefaceCache.AddGlyphTypeface(XGlyphTypeface glyphTypeface)
at PdfSharp.Drawing.XGlyphTypeface.GetOrCreateFrom(String familyName, FontResolvingOptions fontResolvingOptions)
at PdfSharp.Drawing.XFont.Initialize()
at PdfSharp.Drawing.XFont..ctor(String familyName, Double emSize, XFontStyle style)