Microsoft has acknowledged that users may encounter printing issues after installing the August 2026 .NET Framework cumulative update, particularly with applications that use certain fonts like Calibri. Some WPF applications may fail with a System.IO.FileFormatException when printing or generating PDF/XPS content. Microsoft has provided a temporary workaround while investigating these issues. Additionally, the KB5121003 update has been linked to problems affecting the gaming community, which Microsoft is also addressing.