title: You currently can't modify MaintenanceWindow with Aurora Serverless - error while updating Cloudformation stack
body: <p>I Have a parameter <code>PreferredMaintenanceWindow</code> setup within <code>AWS::RDS::DBCluster</code> in my cloudformation template and it was all good. 
  Recently I had to add the parameter <code>EnableCloudwatchLogsExport</code> to the template, but when I tried to deploy the stack it failed with the following message:</p>
  
  <blockquote>
    <p>You currently can't modify MaintenanceWindow with Aurora Serverless.
    (Service: AmazonRDS; Status Code: 400; Error Code:
    InvalidParameterCombination; Request ID:
    bf40fd7e-e599-481a-ac23-b3c68e9794a1)</p>
  </blockquote>
  
  <p>This is when I didn't even touch that parameter, did anyone faced such issue or any workaround which I can use with CloudFormation </p>
  
  <p>PS: I am aware that I can setup the <code>EnableCloudwatchLogsExport</code> from the CLI but I don't want drift and I would really want it to do it via cloudformatio.</p>
  
  <p>Update:</p>
  
  <pre><code>RDSServerlessDB:
      Type: "AWS::RDS::DBCluster"
      Properties:
        AvailabilityZones:
          Fn::GetAZs: !Ref 'AWS::Region'
        BackupRetentionPeriod: 3                                                # Number of days
        DatabaseName: !Join ["_", [!Join ["_", !Split [ "-", !Sub '${MasterStack}']], 'fol']]
        DBClusterParameterGroupName: "default.aurora5.6"
        DBSubnetGroupName: !Ref RDSDBSubnetGroup
        EnableCloudwatchLogsExports:
          - error
          - general
          - slowquery
          - audit
        Engine: "aurora"
        EngineMode: "serverless" 
        #      EngineVersion: "5.6.10a"
        MasterUsername: "username"                                            
        MasterUserPassword: "{{resolve:ssm-secure:/password:1}}"
  #      Port: 3306
  #      PreferredMaintenanceWindow: "sun:01:00-sun:03:00"
        ScalingConfiguration:
          AutoPause: True
          MaxCapacity: 32
          MinCapacity: 2
          SecondsUntilAutoPause: 300
        Tags:
          - Key: owner
            Value: !Ref StackOwner
          - Key: task
            Value: !Ref Task
        VpcSecurityGroupIds:
          - Ref: RDSSecurityGroup
  </code></pre>