Boot failures after updating Bluefin to 43.20260113 can be caused by several known issues:

• Disk space exhaustion: If partitions like /, /etc, or /boot are full or out of inodes, the system may fail to boot. Use a live USB to free up space, as Bluefin does not provide a writable rescue mode if both deployments are read-only. See issue #3663
• SELinux context problems: SELinux denials can prevent boot. Try booting in permissive mode or relabel with sudo restorecon -Rv /sysroot/ostree. See issue #2599
• /etc becoming read-only: If you use systemd-confext or overlays, /etc may become read-only. Unmerge or refresh those extensions. See issue #2266
• AMD GPU driver regressions: These can cause black screens or failed boots. Try booting an older deployment or kernel. See issue #3908
• Recent /boot cleanup changes: Custom /boot or bootloader configs may be affected by recent changes to /boot cleanup scripts. See pull request #3986

To troubleshoot, check disk space and inodes, review SELinux logs, verify /etc is writable, and try older deployments or kernels if GPU issues are suspected. Provide specific failure symptoms (e.g., hang, emergency shell, black screen) and additional logs for more targeted help.