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In a fresh development, microsoft has now admitted that one of the updates dropped on Patch Tuesday is to blame. After Microsoft dropped updates for Windows 11 on August’s Patch Tuesday, users have been reporting problems with their printers and with the creation of PDFs.

According to the latest update, the problematic patch is KB5120708, which isn’t actually for Windows 11 itself but rather affects the .NET Framework.

According to the latest update, microsoft confirms that, following the installation of this patch, some applications may encounter errors when printing from documents containing certain common fonts, or when creating PDF or XPS files:.

Industry observers note that known Issues: After installing the August 2026 .NET Framework cumulative patch, some WPF applications may fail with a System.IO.FileFormatException when printing or generating PDF/XPS content that uses certain fonts, including Calibri.

In a fresh development, the matter is still being investigated, but in the meantime you can use a temporary workaround if you’re experiencing these issues:.

In a fresh development, workaround: Applications may mitigate the issue by enabling the Switch.MS.Internal.TtfDelta.DisableCmapAndSbitOverflowProtection AppContext switch in the app config file, as shown below.

As part of the ongoing story, microsoft recommends using this workaround only as a temporary measure and only when required to address this issue. This switch disables security protections introduced in the August 2026 patch and may increase exposure to the vulnerabilities addressed by that patch.

As part of the ongoing story, yesterday, Microsoft admitted that the KB5121003 patch was also causing problems, primarily affecting gamers. August 2026’s Patch Tuesday is turning into an ever-growing disaster for Windows 11 users.

In a fresh development, this article originally appeared on our sister publication PC-WELT and was translated and localized from German.

As part of the ongoing story, he has been writing on almost all IT topics for around 25 years, covering everything from news to reviews and buying guides. Hans-Christian Dirscherl began his IT life with Autoexec.bat and config.sys, Turbo-Pascal and C, Sinix and Wordperfect.