azure depolyment template virtual machine

Question

Hi there

I keep getting this error when using custom deployment template, what is fxChanged?
{"code":"DeploymentFailed","message":"At least one resource deployment operation failed. Please list deployment operations for details. Please see https://aka.ms/DeployOperations for usage details.","details":[{"code":"InvalidJson","message":"Could not find member '__fxChanged' on object of type 'SubnetProperties'. Path 'properties.subnets[0].properties.__fxChanged', line 1, position 188."}]}

Thanks
Levino