J600f u3 imei repair failde

Welcome to Octoplus Box Samsung software version 2.7.9
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Platform: Samsung Android
Selected port: COM3
Selected model: SM-J600F
Operation: Repair IMEI A
Please, press "OK" button on the phone to allow USB debugging.
Detected phone model: SM-J600F
Firmware compiled date: Mon Nov 12 10:43:12 KST 2018
PDA version: J600FXXU3ARK1
CSC version: J600FOJM3ARK1
SW version: J600FXXU3ARK1
Phone SN: RF8K60DTWVH
Android version: 8.0.0 (R16NW)
Sales code: PAK
Country: PAKISTAN
HW platform: exynos5
HW Chip: exynos7870
HW Modem: SHANNON315
Security patch level: 2018-11-01
Warranty Void: 0
SIM 1 status: absent
SIM 2 status: absent
Codename: j6ltecis
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Connecting to server ..
Username: amiscomputer
Connect to server successfull.
Checking smart card...
Smart card successfully checked.
Your balance: 100 credits.
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Checking operation...OK
Initializing...OK
Rebooting phone
Searching for a phone. Please wait...OK
Please keep phone's screen active!
Initializing exploit...
cant start elf
Write IMEI failed
Performed by 2.7.9.4 Software versin.
all mobile show elf error.pleas give me solution octopus team.