I am trying to install 16.04LTS on an Asus X554L laptop. It previously had Windows 10, which became corrupted, and I had no desire to repair or reinstall Windows, and since I had been using Linux for almost 10 years now I decided to install Ubuntu on it (I also tried Debian). The installation can only be booted through UEFI, and it usually runs fine at first, but near the end it tells me that the installation of GRUB signed keys has failed.
Options for Secure Boot, CSM, and boot override within BIOS have been locked out of the user's ability to edit. Secure Boot is enabled, and CSM is disabled. I am still able to boot the Ubuntu installer (not Debian), however the computer refuses to boot the OS after it is installed. The only related option I am able to edit is insert or delete "Secure boot variables" which are the proprietary keys Ubuntu is lacking to install GRUB onto MBR.
Deleting all secure boot keys prevents the comptuer from booting the installers kernel, it just drops at the grub console