BC68 returns error number 4 after NSOSTF command

Hello, the BC68 is returning error number 4 after message send command. Im connected to the network (cereg) and created socket number 1 (udp) - any ideas?

AT+NSOSTF=1,18.66.1.13,12346,0x200,54,86772303011569407700382C53683E90B800000001010000000000000000FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
+CME ERROR: 4

Firmware version:
SSB,V150R100C10B200SP1
SECURITY_A,V150R100C20B300SP2
PROTOCOL_A,V150R100C20B300SP2
APPLICATION_A,V150R100C20B300SP2
SECURITY_B,V150R100C20B300SP2
RADIO,Hi2115_RF1

Thanks for any leads!
Marcel

Hi Marcel
AT+NSOCR=DGRAM,17,0,1 //Create a UDP type Socket, and receive transmission messages
1 //Number returned by socket
OK
AT+NSOSTF= corresponds to the socket number returned by AT+NSOCR.