Microsoft announced it pulled four of the security updates it issued earlier this month after users reported crashes and bootup issues. The updates include 2982791, 2970228, 2975719, and 297533, they apply to Windows Vista, Windows 7, Windows 8, Windows 8.1, Windows RT and Windows Server 2003.
The software giant explains on its website that they've discovered three issues with the aforementioned patches. The first two issues are related to fonts, including issues with fonts not loading or not rendering correctly after installing the updates. The third issue is more serious, Microsoft reports they're investigating issues in which systems may crash with a 0x50 Stop error message. This issue may be persistent and prevent systems from booting correctly.
More info and ways to mitigate the issues can be found at Microsoft.