Default [Q] Restoring Stock Rom

Hi

I have recently decided to unroot and re-lock my bootloader. I tried using the KDZ updater method and I followed all the steps of the guide. This error message keeps popping up, and my phone just reboots from download mode to fastboot mode:

16:22:13 : Launching SW update
16:22:13 : Unpacking KDZ
16:22:20 : KDZ file extraced
16:22:38 : Files were extracted.
16:22:38 : LGMobileDL Load.
16:22:38 : Port = -1
16:22:38 : Connecting to phone
16:22:50 : Check Phone mode = 2
16:22:50 : Phone type check.......
16:22:50 : LGMobileDL.DLL Loading....
16:22:50 : _SetAuthMark Fail
16:22:50 : AuthMark가 정확히 Phone에 Write 되지 않았습니다!
16:22:50 : _SetAuthMark Fail
16:22:50 : LoadCDMAPhoneData() Error
16:22:50 : _DetachDLL Call
16:22:50 : _DetachDLL Call End
16:22:50 : Param : Path = C:\ProgramData\LGMOBILEAX\Phone\E97510H_00.dz
16:22:50 : Param : moduleDir =
16:22:50 : Param : waitTime = 0
16:22:50 : Param : UsbHighSpeed = 1
16:22:50 : Param : PhoneMode = 2
16:22:50 : Param : BinVersion = E97510H_00
16:22:50 : Param : AuthMark = 0
16:22:50 : Call fn_StartUpgrade
16:25:46 : CDMA: wParam = 100, lParam = 210
16:25:46 : Step : Upgrade Error2 - Error Code : 210
16:25:46 : ResetStartInfo() Call
16:25:46 : _DetachDLL Call
16:25:46 : _DetachDLL Call End
16:25:46 : FreeLibrary Call
16:25:46 : FreeLibrary Call End
16:25:46 : ResetStartInfo() Call End
16:25:46 : ===FINISHED===
16:33:05 : OnModelDllMsg(OnMsgFromModelDll-CDMA) delete m_pLGCyonUpdate

Any idea how to resolve this? I have read several threads on this but I haven't seen a solution to this problem. Thanks alot.
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Guides:
[GUIDE] What to do if my phone doesn't turn on?

Device: LG Optimus G E975
ROM: ARTMOD v5.2.1 Kitkat
Custom Recovery: PhilZ Touch Recovery