SM-A520f unlock error [Need more information]

Searching Samsung modem ... detected COM73
Reading phone info ...
Model: SM-A520F
AP version: A520FXXU5CRGB
CSC version: A520FOLB5CRF8
CP version: A520FXXU5CRF8
Product code: XXV
Phone SN: R58K24KNSPV
IMEI: 356650092219239
Unique number: CBJ005FA5EA1C15
Reading IMEI ... OK
IMEI: 356650092219239
Reading SN ... error (1)