New Windows Server emergency updates fix container launch issue

Microsoft has released emergency Windows Server updates to address a known issue preventing Windows containers from launching. The issue affects only containers running under Hyper-V isolation mode, which allows multiple containers to run simultaneously on a single Windows host inside separate virtual machines. "This update fixes an issue caused by 2025.04 B container images released on April 8, 2025 where Windows containers running in Hyper-V isolation mode could fail to start in some cases if their update level didn't match that of the hosting utility virtual machine (UVM)," Microsoft explained. "The mismatch caused compatibility problems between system files, leading to startup failures. With this update, containers now correctly access the necessary system files from the host, improving reliability and compatibility across different Windows versions." After deploying this week's emergency updates, containers will now correctly access the necessary system files from the Windows ... Read full article.