Cannot connect to mqtt by using esp32 - c

Question

WiFi connected
IP address:
192.168.1.xxx
Attempting MQTT connection...connected
Guru Meditation Error: Core 1 panic'ed (IllegalInstruction). Exception was unhandled.
Memory dump at 0x400d25bc: ee650213 00f01d0a 41004136
Core 1 register dump:
PC : 0x400d25c1 PS : 0x00060930 A0 : 0x00000000 A1 : 0x3ffb4010
A2 : 0x75e82caf A3 : 0x75e82caf A4 : 0x3ffc2f84 A5 : 0x00000000
A6 : 0x00000000 A7 : 0x00000000 A8 : 0x800d24dc A9 : 0x3ffb3ff0
A10 : 0x00000001 A11 : 0x00000001 A12 : 0x00000010 A13 : 0x3ffc2f84
A14 : 0x3ffb927c A15 : 0x80000001 SAR : 0x0000000a EXCCAUSE: 0x00000000
EXCVADDR: 0x00000000 LBEG : 0x40084415 LEND : 0x4008441d LCOUNT : 0x00000026
Backtrace:0x400d25be:0x3ffb4010
ELF file SHA256: 0000000000000000
Rebooting...
ets Jun 8 2016 00:22:57
rst:0xc (SW_CPU_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:1
load:0x3fff0030,len:1344
load:0x40078000,len:13864
load:0x40080400,len:3608
entry 0x400805f0
Connecting to xxx
Guys, i got bugged when connecting to mqtt server. I'm using ESP32.
Here is my code for connecting.
void connectMQTT(void *pvParameters) {
vTaskDelay(6000 / portTICK_PERIOD_MS);
while (!client.connected()) {
Serial.print("Attempting MQTT connection...");
String clientId = "FreeRTOS";
clientId += String(random(0xffff), HEX);
if (client.connect(clientId.c_str())) {
Serial.println("connected");
client.subscribe("denled");
} else {
Serial.print("failed, rc=");
Serial.print(client.state());
Serial.println(" try again in 2 seconds");
delay(2000 / portTICK_PERIOD_MS);
}
}
}
Here is my task. The default running core on my arduino ide is 1
xTaskCreatePinnedToCore(
connectMQTT
, "MQTTConnection" // Task name
, 2048 // Stack size (bytes)
, NULL
, 3 // Priority
, NULL
, ARDUINO_RUNNING_CORE);
Thanks for reading. This is the first time i post, so if there any feedback is always good for me