Microsoft .NET Update Causes Printer Problems for Some Users

Microsoft's recent .NET Framework cumulative update has been causing issues for some users. The update, released on August 11, is meant to fix various problems but has instead led to printer problems for Windows 10 and 11 users.

The issue affects WPF applications that use certain fonts, including Calibri, the default font in Microsoft Word. When printing or generating PDF/XPS content, these apps may fail with a System.IO.FileFormatException.

Microsoft recommends using a workaround to enable Switch.MS.Internal.TtfDelta.DisableCmapAndSbitOverflowProtection in the app config file. However, this tweak carries its own risks and is only suggested as a temporary fix.