I also have this problem on both an imac mid 2011 and an imac late 2013. Both in-place upgrades and booting of the 25.04 upgrades fail. They boot to grub but beyond that you get a black screen with a steady cursor.
I've found prople on forums reporting this problem on macbooks, imacs and mac minis. It seems to be related to the kernel that 25.04 ships with. You can boot 25.04 with older kernels. https://askubuntu.com/questions/1546074/kernel-problem-cant- install-25-04-onto-macs?noredirect=1#comment2720603_1546074 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2105402 Title: Plucky fails to boot on (older) Macs To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2105402/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
