Error: Lookup error.

[IECCLES4]

I was following the MQTT tutorial and when I try to run the demonstration of "mosquitto_telemetry" I get this outcome:
Using certificate: /home/dtl-admin/IoTMQTTSample/mosquitto/IoTHubRootCA.crt.pem
Connecting...
Error: Lookup error.
Not sure if anyone else has seen this because I can't find anything about this error.

[wayp123]

in config.h
#define CERTIFICATEFILE "IoTHubRootCA.crt.pem"
put pem file in debug