n900V IMEI REPAIR

IVE BEEN TRYING TO CLEAN THE IMEI OF A NOTE 5 TMOBILE
I KEEP GETTING THIS ERROR. SOMEONE PLEASE TELL ME WHAT IM DOING WRONG. EVERY OTHER PHONE WORKS PERFECTLY FINE. THE ONES I HAVING TROUBLE WITH ARE
N920T
G925V
AND MORE BUT HELP ME WITH THIS ONE. ITS A NOTE 5 TMOBILE

I GET STUCK ON DEACTIVATING MSL
EXECUTING EXPLOIT..
EXPLOIT FAILED.

Platform: Samsung Android
Selected port: COM18
Selected model: SM-N920T
Selected file: C:
Detected phone model: SM-N920T
Firmware compiled date: Fri Dec 4 17:27:12 KST 2015
PDA version: N920TUVS2COKC
CSC version: N920TTMB2COKC
SW version: N920TUVS2COKC
Phone SN: RF8G80XQ92P
Android version: 5.1.1 (LMY47X)
Checking Root:
Phone is Rooted.
Reading security backup, please wait…
Backup saved as
Checking Certificate file…
Certificate file successfully checked
Deactivating MSL…
Executing exploit…
Executing exploit failed
Writing Certificate failed
Performed by 2.2.1 software version