why error?

REPAIR INSTRUCTIONS:
Activate Diagnostic Port:
1. Tap 7 times on 'Build number' in 'Settings'-'About phone' to enable 'Developer options',
go to 'Settings'-'Developer options' and enable 'USB debugging'.
3. Select device in ADB settings.
2. Press 'Activate Diag' button.

Reset EFS, Disable Factory Mode:
Phone must be rooted!
If the software can't root the phone automatically,
then you must root your device manually.
1. Power on the phone.
2. Tap 7 times on 'Build number' in 'Settings'-'About phone' to enable 'Developer options',
go to 'Settings'-'Developer options' and enable 'USB debugging'.
3. Connect the phone to PC with USB cable, install drivers if needed.
4. Select device in ADB settings.
5. Press 'Reset EFS' if you need to reset it.
Be carefully, do not perform this without necessity. Backup will be created automatically.
6. If you have yellow table on your device screen, then press 'Disable Factory Mode' button.

Wipe EFS/NVM:
If you have 'IMEI null/null' or 'Phone baseband unknown' errors,
Then you can try to repair this errors with this function.
1. Power on the phone in download mode (turn off phone, hold Volume Down + Home + Power).
2. Connect USB cable, install drivers if needed.
3. Press 'Wipe EFS/NVM' button to deactivate security.
4. Wait till phone reboot.

Operation: Reset MSL
Selected model: SM-J500H
Selected port: COM33 SAMSUNG Mobile USB Serial Port
Software version: 31.5.1

Reading phone info...
Reading IMEI... OK
IMEI: 354748070430109
Reseting MSL security... error (1)

Done with Samsung Tool PRO v.31.5.1