Description of problem: Macbook Pro (2011, intel mac) and similar models, will hang indefinitely at a gray screen. No GRUB, no errors. Just a gray (possibly black) screen. Version-Release number of selected component (if applicable): shim-x64-15.4-3.x86_64 How reproducible: Always Steps to Reproduce: 1. Boot 2. 3. Actual results: Boot chime -> gray screen -> indefinite hang at that gray screen Expected results: GRUB menu should appear and/or the system should boot and startup to a login prompt. Additional info: This bug has been identified and fixed in shim-unsigned-x64-15.4-3.fc33 and newer and will be fixed in an imminently released shim which all mac users will get by default (eventually). But in the meantime, you might want to get back to the older working shim so you can boot! 1. Boot any Fedora 34 or older netinstaller, live, edition or spin from a USB drive. The one image that will NOT help you is the special shim/grub test day image (either of them). But an ISO from Fedora 33, 32, 31... will work. 2. Use 'lsblk -f' or 'sudo blkid' to find a small HFS+ volume that's used as an EFI System partition on Fedora installations on Macs. This is typically a 200M-600M partition by default. Mount this volume to /mnt. 3. Replace the new shim on the computer's ESP with the old shim on the USB stick: cp /run/initramfs/Live/EFI/BOOT/BOOTX64.EFI /mnt/EFI/BOOT/BOOTX64.EFI cp /run/initramfs/Live/EFI/BOOT/BOOTX64.EFI /mnt/EFI/fedora/shim.efi cp /run/initramfs/Live/EFI/BOOT/BOOTX64.EFI /mnt/EFI/fedora/shimx64.efi You should get an overwrite confirmation for each of these.