While I'm trying to set value for Device.NAT.PortMapping.1.Enable, getting this error

root@arrisgateway:~# dmcli eRT setv Device.NAT.PortMapping.1.Enable bool true
CR component name is: eRT.com.cisco.spvtg.ccsp.CR
subsystem_prefix eRT.
setv from/to component(eRT.com.cisco.spvtg.ccsp.pam): Device.NAT.PortMapping.1.Enable
Execution fail(error code:CCSP_ERR_INVALID_PARAMETER_VALUE(9007)).

Any suggestion regarding this issue?

Thanks in advance!