OIC Integration activation failure in Gen3

Hi,

We have created one OIC integration which involves a REST trigger and one invoke REST connection.

That Integration is getting failed in activation with below error:

Integration AEXP_COM_ITSM_INT_POC2 (1.0) cannot be activated.
Activation request 'AEXP_COM_ITSM_INT_POC2, 01.00.0000, 4322a8f8-2ca6-429d-a2a8-f82ca6329db8' failed with failure:.

There is no specific error message to get an idea of actual problem except for error code OIC_ACTIVATION_UN_HANDLED_ERROR.

We have tried to reconfigure the two REST connections used in Integration in edit mode and also tried to clone the integration.