Could not verify update

I have the D5803 running 5.0.2 (stock rooted) and it recently got an OTA but after the download it says "Could not verify update" is there a way to fix this?

Recovery "Boot certification verify" error

i tried flashing TWRP on my LS980 4.2.2 rooted via rom manager it says my recovery is set to TWRP but when i try to boot into recovery it gives me this boot certification verify error than goes blank anyway to fix this?

[Q] [CloudyG2 3.3] secure booting error boot certification verify

Hi! I have a lg d805, the official stock rom is 4.2.2 (jb) that is a bit useless for many purposes; so I decide to install the rom cloudyg2 3.3 based on lp.
It installed successfully; however , when I try to go to recovery mode I get the mentioned error. is there any way to install twrp directly without flashing to stock rom?
(Sorry for my english, im latin)

Pd: I can enter to download mode normally too.