C sdk agent is not able to send data to server

Hello,

We have a C-SDK based application and it was sending data to the thingworx platform. I have cloned the application into new instance and tried connecting the agent, but agent is not connecting and throwing below error:

2020-09-05 18:59:25,908 TW_SDK--ERROR TW_VALIDATE_CERT: Certificate rejected.  Code: 10, Reason = certificate has expired

I'm using the ThingWorx SDK version: 2.1.2

Can someone please provide inputs to overcome this issue.

-thanks,
Abhiram