That's weird.. You do have the blacklist file installed by the update though (/usr/share/grub-gfxpayload-lists/blacklist/10_lenovo_l420)? What if you run update-grub-gfxpayload by hand?
That's weird.. You do have the blacklist file installed by the update though (/usr/share/ grub-gfxpayload -lists/ blacklist/ 10_lenovo_ l420)? What if you run update- grub-gfxpayload by hand?