Samsung A520f unlocked error help pls

trying to unlocked samsung a520f but keep getting this error

here is the logs

Checking Login and Password... OK
Ballance: 50 crd.
You have 50 credit(s) left. This operation takes 5 credits.Continue? Yes
Searching Samsung modem... detected COM1143
Reading phone info...
Model: SM-A520F
AP version: A520FXXU4BRB1
CSC version: A520FPHE3BQL2
CP version: A520FXXU4BRAH
Product code: PHE
Phone SN: R58J60SF20R
IMEI: 3586510xxxxxxxx
Unique number: CBJ1087684C1834
Searching Samsung diag port... detected COM256
Reading phone info... error (0)
Check phone connection or KNOX WARRANTY VOID is 0x1

Done with Samsung Tool PRO v.31.5.1