Issue to Add New Sensor

Hello Everybody

I am having some issue to add a new sensor in my dashboard.
I received the following message when I am trying to add a new sensor

Error retrieving JSON data from Sensorgateway
And
No output controls have been found on the device with IP 172.20.4.251

However, I can ping the Sensor IP.

I also check the Manual Page 88 and found answers just for email alerts issues.

Hello Sensor Error, have you tried to check the manual on page 96 and 97 for integration using JSON?http://manuals.serverscheck.com/InfraSensing_Sensors_Platform.pdf