This isn't related to grub. The LUKS password prompt is on one of the text ttys ( switch ttys to find it ) and waiting for you to unlock the volume. The prompt is on a tty because plymouth is not installed into the initramfs because it has no themes installed. It seems that lubuntu-core depends on a theme and so should pull it in, but lubuntu- core is not being installed either.
** Package changed: grub2 (Ubuntu) => lubuntu-meta (Ubuntu) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1529314 Title: Newly installed Xenial (encrypted LVM) will not boot To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/lubuntu-meta/+bug/1529314/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
