I had the same issue whn upgrading from 17.10 to 18.04 and used the following workaround:
cd /boot mkdir unsigned mv vmlinuz-4.10.0-40-generic vmlinuz-4.10.0-42-generic vmlinuz-4.13.0-46-generic unsigned/ apt-get upgrade and voila problem solved :-) It seems that unsigned kernels are left in the /boot directory (not used it seems) which prevents the grub update mechanism to happen correctly. So I think the "design" is wrong and that unsigned kernel in SB mode should just be ignored and shouldn't prevent the postinstall to proceed. Just my 0.02€ and YMMV of course -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1788727 Title: upgrade crashing due to unsigned kernels To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1788727/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
