Microsoft released its monthly Patch Tuesday security updates, which included dynamic updates and new .NET Framework versions. Users of Windows 11, Windows 10, and Windows Server are experiencing printing issues after installing the August 2026 .NET Framework cumulative updates, particularly with Windows Presentation Foundation (WPF) applications that fail during printing tasks or when generating PDF or XPS documents. The problems are linked to specific fonts, notably Calibri, and may result in a System.IO.FileFormatException. Microsoft has provided a temporary workaround involving an AppContext switch, but enabling this switch disables certain security protections from the August 2026 update, potentially exposing applications to vulnerabilities. No permanent fix or timeline for one has been provided.