SM-G925W8 5.1.1 Unlock failed

hi octopus team and gsmhosting family.

i have a problem unlocking s6 edge G925w8 android 5.1.1

i cant basically unlock it. its always "Executing exploit failed"

i also tried to downgrade it but its always stuck on samsung logo that way.

Please check the log below.

Thanks in advance.

P.S if there is solution on forum, forgive me i just cannot find it.

Welcome to Octoplus/Octopus Box Samsung software version 2.1.6
Platform: Samsung Android
Selected port: COM100
Selected model: SM-G925W8
Detected phone model: SM-G925W8
Firmware compiled date: Tue Nov 10 19:39:02 KST 2015
PDA version: G925W8VLU3BOK1
CSC version: G925W8OYA3BOK1
SW version: G925W8VLU3BOK1
Phone SN: R58G31XXXXX
Android version: 5.1.1 (LMY47X)
Checking Root:
Phone is Rooted.
Reading security backup, please wait…
Backup saved as C:\Program Files (x86)\Octoplus\Octoplus_Samsung
Deactivating MSL…
Executing exploit…
Executing exploit failed
Phone unlocking failed