We faced with crashing of printing task from WPF in .Net Framework 4.6. There was some changes in CultureInfo.
When we try to print DrawingVisual with ForamtedText that have culture set to System.Globalization.CultureInfo.InvariantCulture. There is no any exception or warning but printing crashes when we print on any printer real or virtual.
We have made an improvement. The problem is fixed in build v.2015.1.16 from 2015.08.07.
If you can't upgrade for any reason, you could see status of the bug report on Microsoft Connect.