a520f error read cert diag on rev4

Operation: Read CERT DIAG
Selected model: SM- A520F
Software version: 30.8

Searching Samsung modem... detected COM5
Reading phone info... OK
Model: SM-A520F
AP version: A520FXXU4BRB6
CSC version: A520FOJV4BRB1
CP version: A520FXXU4BRAH
Product code: MID
Phone SN: R28JA3417RH
Unique number: CBJ1001A9EAFF74
Searching Samsung diag port... detected COM4
Reading phone info... OK
CP version: A520FXXU4BRAH
CP build: Jan 30 2018 08:46:21
Reading data from phone... error (1)

Done with Samsung Tool PRO v.30.8