i also having a similiar issue like this after i tried security update 2018-002 for 10.13.6, here is the screenshot :
thx before
I was getting a similar screen when I tried to do the update. I just got it to install after a few tries. Here's what I did:
first failure happened downloading the update as normal booted up from my regular macOS partition. when I restarted, it put me right back to the clover boot loader and trying to boot from the install partition or install pre booter would lead me to the error screen you had.
What worked for me:
randomly i decided to work my way left to right across the clover boot loader icons, and i started by booting my computer from the "boot file vault prebooter from preboot" it brought me to my regular desktop, so I went to the app store and re downloaded the update. this time, when I hit restart, it said it was installing some stuff for a little bit, then restarted straight to a progress bar loading screen. eventually it restarted again and I ended up back at my clover boot loader menu. I tried booting from the "pre boot install something" option and it gave me a circle with a line thru it, so probably don't click that. I moved on to the "install macOS something" option and that continued my installation. i think it restarted again, then i chose my regular macOS drive, booted, updated nvidia drivers, and done.
TLDR:
booting from the "boot file vault prebooter from preboot" partition and starting the install from there seemed to work for me when I was getting errors installing.
unhide any boot partitions in the gui section of clover configurator on your config.plist
restart and boot from the "boot file vault prebooter from preboot" option in the clover boot loader
go to app store, download update, restart
update should start installing, computer will restart,
boot from the "install macOS something or other" option, install continues, computer restarts
boot from your regular macOS partition
update nvidia drivers