"Route did not stabilize in expected time" on CloudFromation

This error occurred via template below:

...

  PNNatGateway:
    Type: 'AWS::EC2::NatGateway'
    Properties:
      AllocationId: eipalloc-xxxxxx
      SubnetId: !Ref PNPublicSubnet
  PNPrivateRouteTable:
    Type: 'AWS::EC2::RouteTable'
    Properties:
      VpcId: !Ref PrivateNet
  PNPrivateRoute:
    Type: 'AWS::EC2::Route'
    Properties:
      RouteTableId: !Ref PNPrivateRouteTable
      DestinationCidrBlock: 0.0.0.0/0
      GatewayId: !Ref PNNatGateway

...

FIX

It fixed when I changed GatewayId to NatGatewayId

...

  PNNatGateway:
    Type: 'AWS::EC2::NatGateway'
    Properties:
      AllocationId: eipalloc-xxxxxx
      SubnetId: !Ref PNPublicSubnet
  PNPrivateRouteTable:
    Type: 'AWS::EC2::RouteTable'
    Properties:
      VpcId: !Ref PrivateNet
  PNPrivateRoute:
    Type: 'AWS::EC2::Route'
    Properties:
      RouteTableId: !Ref PNPrivateRouteTable
      DestinationCidrBlock: 0.0.0.0/0
      NatGatewayId: !Ref PNNatGateway

...

What a unkind error message it is!