Cloudformation - Route table has a conflicting association with the gateway - amazon-web-services

Question

I'm trying to deploy EC2 instance using cloudformation, It's giving the following error when i try to execute the stack.
Route table has a conflicting association with the gateway igw-0d7bbb47c8b4e8875 (Service: AmazonEC2; Status Code: 400; Error Code: RouteConflict; Request ID: 0ca161d0-b58d-4f95-a2f1-01038ccc4cae; Proxy: null)
Parameters:
InstanceType:
Type: "String"
Default: t2.micro
Image:
Type: "String"
Default: ami-0aab712d6363da7f9
Resources:
WebServer:
Type: AWS::EC2::Instance
Properties:
AvailabilityZone: ap-southeast-2a
KeyName: poweruser-keypair
InstanceType: !Ref InstanceType
ImageId: !Ref Image
SubnetId: !Ref SubNet
VPC:
Type: AWS::EC2::VPC
Properties:
CidrBlock: "10.0.0.0/16"
InstanceTenancy: default
SubNet:
Type: AWS::EC2::Subnet
Properties:
AvailabilityZone: ap-southeast-2a
MapPublicIpOnLaunch: true
CidrBlock: "10.0.0.0/24"
VpcId: !Ref VPC
InternetGateway:
Type: AWS::EC2::InternetGateway
IgwAttachment:
Type: AWS::EC2::VPCGatewayAttachment
Properties:
InternetGatewayId: !Ref InternetGateway
VpcId: !Ref VPC
RouteTable:
Type: AWS::EC2::RouteTable
Properties:
VpcId: !Ref VPC
RoutingToInternet:
Type: AWS::EC2::Route
DependsOn: IgwAttachment
Properties:
RouteTableId: !Ref RouteTable
DestinationCidrBlock: 0.0.0.0/0
GatewayId: !Ref InternetGateway
SubnetRouteTableAssociation:
Type: AWS::EC2::SubnetRouteTableAssociation
Properties:
RouteTableId: !Ref RouteTable
SubnetId: !Ref SubNet
SubnetNetworkAclAssociation:
Type: AWS::EC2::SubnetNetworkAclAssociation
Properties:
SubnetId:
Ref: SubNet
NetworkAclId:
Ref: NetworkACL
NetworkACL:
Type: AWS::EC2::NetworkAcl
Properties:
VpcId: !Ref VPC
NACLEntry:
Type: AWS::EC2::NetworkAclEntry
Properties:
CidrBlock: "10.0.0.0/16"
Egress: true
NetworkAclId: !Ref NetworkACL
Protocol: -1
RuleAction: "allow"
RuleNumber: 100

Answer 1

There is nothing wrong with your cloudformation template. This means that the code that you used in the question is not fully representative of your actual template that you use.