Mosquitto cannot find ca cert file


I am configuring mosquitto to work bridged with AWS IoT.

I have been following the instructions here:
and my mosquitto configuration file is:

# AWS IoT endpoint, use AWS CLI 'aws iot describe-endpoint'
connection awsiot

# Specifying which topics are bridged
topic garage/door both 1

# Setting protocol version explicitly
bridge_protocol_version mqttv311
bridge_insecure false

# Bridge connection name and MQTT client Id,
# enabling the connection automatically when the broker starts.
cleansession true
clientid bridgeawsiot
start_type automatic
notifications false
log_type all

# =================================================================
# Certificate based SSL/TLS support
# -----------------------------------------------------------------
#Path to the rootCA
bridge_cafile /etc/mosquitto/certs/AmzonRootCA1.pem

# Path to the PEM encoded client certificate
bridge_certfile /etc/mosquitto/certs/4745e52bf9-certificate.pem.crt

# Path to the PEM encoded client private key
bridge_keyfile /etc/mosquitto/certs/4745e52bf9-private.pem.key

The error I am getting is: “1555847480: Error: Unable to load CA certificates, check bridge_cafile “/etc/mosquitto/certs/AmzonRootCA1.pem”.”

Clearly I am not doing the right thing with the certs I am uploading through “configurator”.

Can anyone please advise where I am going wrong?