CloudFormation broke my "AWS::ElasticLoadBalancingV2::Listener Certificate" configuration

Question

Last week I created an ECS stack which included an ELBv2 resource and an https listener:
```
    "Listeners": [
      { "Port": 443,
        "Protocol": "https",
        "Certificates": [{ "Ref":"ParamDefaultCert" }],
```

Everything worked fine in 2 of the 3 AWS accounts that I created it in.  Then on the 3rd account I got an error about the “Certificates” parameter expecting a JSONObject and not a String.  I thought it was weird that I used the exact same CFN template in 2 other accounts and it worked but failed in the 3rd one.

I checked the documentation, and sure enough, it lists a JSONObject.   Oh well, maybe I messed up somewhere.

So I changed my template to follow [the documentation](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-elasticloadbalancingv2-listener-certificate.html):
```
    "Listeners": [
      { "Port": 443,
        "Protocol": "https",
        "Certificates": [{ "CertficateArn": { "Ref":"ParamDefaultCert" }}],
```
and rebuilt the CFN stack.

Wouldn’t you know it, now 2 out of the 3 AWS Account accept the new configuration but the 3rd one now gives me this error:
```
Resource handler returned message: 
"Model validation failed (#: extraneous key [CertficateArn] is not permitted)" 
(RequestToken: 20037927-eb59-9c8a-3d1a-d55c573052f5, HandlerErrorCode: InvalidRequest)
```

What the heck is going on with CFN?!?!?!

Accepted Answer

Hello.

I thought it might be a spelling mistake.  
Try making your template like this:  
CertficateArn→CertificateArn  
```
    "Listeners": [
      { "Port": 443,
        "Protocol": "https",
        "Certificates": [{ "CertificateArn": { "Ref":"ParamDefaultCert" }}],
```

In the document below, it is "CertificateArn" and your template is "CertificateArn".  
Your template is missing the "i" in "CertificateArn".  
https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-elasticloadbalancingv2-listener-certificate.html

CloudFormation broke my "AWS::ElasticLoadBalancingV2::Listener Certificate" configuration

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