Seeeduino Cloud and Grove IoT Starter Kit issues

I get root-CA.crt from amazon, but always fail in
if((rc = myClient.config(AWS_IOT_MQTT_HOST, AWS_IOT_MQTT_PORT, AWS_IOT_ROOT_CA_PATH, AWS_IOT_PRIVATE_KEY_PATH, AWS_IOT_CERTIFICATE_PATH)) == 0) {
the rc code is -13

screen out put is:
AWS IoT SDK Version(dev) 1.1.1-

temperature
Connect failed!
-13

my box path is:
AWS IoT SDK Version(dev) 1.1.1-

temperature
…/certs/root-CA.crt
0
file no exit1
Connect failed!
-13

Do anybody real use “Seeeduino Cloud and Grove aws IOT start kit” and is working?

The error -13 is:
the specified credentials are not found on OpenWRT
code is error in:
myClient.connect()

Do you know what tha means, I follow our the instruction, just rootCA.crt is copy from
aws-iot-device-sdk-arduino-yun
3. Download the AWS IoT CA file from here.

I fix the issue, I miss the CA file. Thanks