MC60E problem with MQTT commands [+CME ERROR: 3518]

Hello,

We are having troubles using the MQTT AT commands on MC60E. I am attaching the commands log where you can see the +CME ERROR: 3518.

I cant find any information about this error code.

17/9/2019 12:45:39.02 [RX] - ATE0

OK
AT+CGMR

Revision: MC60ECAR01A05

OK

17/9/2019 12:45:39.63 [RX] - AT

OK
AT+CMEE=1

OK

17/9/2019 12:45:40.22 [RX] - AT+CPIN?

+CPIN: SIM PIN

OK

AT+CPIN=0000

+CPIN: READY

OK

AT+CPIN?

+CPIN: READY

OK

AT+CSDH=0

OK

17/9/2019 12:45:41.86 [RX] - AT+CREG?

+CREG: 0,2

OK

17/9/2019 12:45:42.95 [RX] - AT+CREG?

+CREG: 0,2

OK

17/9/2019 12:45:43.66 [RX] -
Call Ready

17/9/2019 12:45:44.04 [RX] - AT+CREG?

+CREG: 0,1

OK
AT+QICSGP=1,“internet.vodafone.gr”,"",""

OK
AT+QIMUX=0

OK
AT+QHREGPP=“internet.vodafone.gr”,"",""

OK

17/9/2019 12:45:44.80 [RX] - AT+CGATT?

+CGATT: 0

OK

SMS Ready

17/9/2019 12:45:48.49 [RX] - AT+CGATT?

+CGATT: 1

OK
AT+QIACT

OK
AT+QILOCIP

100.107.148.156

17/9/2019 12:47:02.15 [RX] - AT+QMTOPEN=0,“broker.mqttdaboard.com”,8000

OK

17/9/2019 12:47:03.99 [RX] -
+QMTOPEN: 0,4

17/9/2019 12:47:07.05 [RX] - AT+QMTOPEN?

OK

17/9/2019 12:47:10.89 [RX] - AT+QMTCONN=?

+QMTCONN: (0-5),""[,""[,""]]

OK

17/9/2019 12:47:25.73 [RX] - AT+QMTCONN=0,"clientId-magJGAaH"

+CME ERROR: 3518

Dear Sir,
As you know that the return value of AT+QMTOPEN means that you Failed to parse domain name, so please check whether the MQTT server you used is normal now or try more times, or you can change another server to have a try. Thanks!
By the way, you can set AT+CMEE=2, then it will return the real reason not 3518. Thanks!