I did a fresh install of 16.04, and experienced the same behavior as is described here: http://askubuntu.com/questions/761864/ubuntu-16-04-booting-in-insecure-mode-message-even-when-turned-off-manually-in
So, now secure boot is turned off, but I still have the delayed startup process and the annoying message everytime I boot.
I did a fresh install of 16.04, and experienced the same behavior as is described here: http:// askubuntu. com/questions/ 761864/ ubuntu- 16-04-booting- in-insecure- mode-message- even-when- turned- off-manually- in
So, now secure boot is turned off, but I still have the delayed startup process and the annoying message everytime I boot.