Cloudformation IAM角色超时“资源没有稳定”

Question

我有一个在IAM角色创建过程中遇到超时的云形态模板：

Role XXX is not stabilized

这是有问题的资源：

"LambdaExecutionRole": {
  "Type": "AWS::IAM::Role",
  "Properties": {
    "AssumeRolePolicyDocument": {
      "Statement": {
        "Effect": "Allow",
        "Principal": {
          "Service": "lambda.amazonaws.com"
        },
        "Action": "sts:AssumeRole"
      }
    },
    "Policies": [
      {
        "PolicyName": "WriteLogs",
        "PolicyDocument": {
          "Statement": {
            "Effect": "Allow",
            "Action": [
              "logs:CreateLogGroup",
              "logs:CreateLogStream",
              "logs:PutLogEvents"
            ],
            "Resource": {
              "Fn::Join": ["", [
                "arn:aws:logs:*:*:log-group:/aws/lambda/",
                {
                  "Ref": "AWS::StackName"
                },
                "-*"
              ]]}
          }
        }
      },
      {
        "PolicyName": "CreateStack",
        "PolicyDocument": {
          "Statement": {
            "Effect": "Allow",
            "Action": [
              "cloudformation:CreateStack"
            ],
            "Resource": "*"
          }
        }
      }
    ]
  }
}

任何想法我可能做错了什么？