[HELP] Error bootloader signature when revert to Stock topic

Hello All,
sorry for my bad english.
I've HTC m7:

tampered
Locked
s-on

whit fastboot getvar all:
(bootloader) version: 0.5
(bootloader) version-bootloader: 1.44.0000
(bootloader) version-baseband: 4A.14.3250.13
(bootloader) version-cpld: None
(bootloader) version-microp: None
(bootloader) version-main: 1.29.401.12
(bootloader) version-misc: PVT SHIP S-ON
(bootloader) serialno: Sxxxxxxxx
(bootloader) imei: 357xxxxxxxx
(bootloader) meid: 00000000000000
(bootloader) product: m7_ul
(bootloader) platform: HBOOT-8064
(bootloader) modelid: PN0710000
(bootloader) cidnum: HTC__001
(bootloader) battery-status: good
(bootloader) battery-voltage: 4280mV
(bootloader) partition-layout: Generic
(bootloader) security: on
(bootloader) build-mode: SHIP
(bootloader) boot-mode: FASTBOOT

When I try to flash RUU.zip I have this error:

writing 'zip'...
(bootloader) signature checking...
FAILED (remote: 12 signature verify fail)
finished. total time: 0.305s

I've try different ruu from m7guru but not work.
Any suggestion? I've to restore stok for warranty shipment

[Q] Revert to Stock? topic

Hey there. I decided to root my phone a while ago.. got unlocked bootloader and CM11 running on it right now. is there any way I can revert to total ORIGINAL stuff? as in the stock firmware? like its supposed to be?
I got no backup.
its rooted.
unlocked bootloader.
CWM CM11 on it.
no issues with it. just wondering if i can get back to stock.

[Q] How revert to Stock Rom ? but keep reovery topic

I have CM12 Maclaw , and TWRP Recovery.
I made a nandro backup with TWRP.
I want to revert and stay in stock Rom my S3 mini model is I8190L, from Latin America, company name Personal.
I want still have root access.
how i can make this, i must do a clean install and flash which file (were i get it)?
Other thing if i am in stock rom i can easily go to cm maclaw rom or stock rom restoring a nandro backup that i have storage for example? is this possible ?