Cookie “_mkto_trk” has been rejected for invalid domain using Marketo Munchkin Extension in Adobe Experience Manager Site.

[VictoriaWang]

We’re facing the problem of Munchkin cookie being rejected due to invalid domain on our AEM site, and we’re wondering if anyone can advise or give us some hints?

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Expected Result: Initial Munchkin cookie in our AEM site (https://publish-xxxxxx.adobeaemcloud.com) via Adobe Data Collection (the tag manager on Adobe Experience Platform)

Our Steps: 

1. Set Tag Property as “adobeaemcloud.com” in Adobe Experience Platform > Data Collection. 
2. Install Marketo Munchkin Extension on Adobe Experience Platform, add Munchkin.ini rule
3. Add data collection script in AEM. 
4. Load the page (https://publish-xxxxxx.adobeaemcloud.com)
5. Munchkin.js is successfully launched, but Cookie “_mkto_trk” has been rejected for invalid domain.

What We’ve tried: 

1. Set the domainLevel to 2 in Marketo Munchkin Extension, but it won’t build in Adobe Experience Platform. 
2. Replace the js in head using Adobe Debugger using initMunchkin() script.
   
   

Appreciate anyone can give us some hints.

[SanfordWhiteman]

Please link to your actual site without obfuscation so we can help you troubleshoot.

[VictoriaWang]

Hello Sanford,

Here's our test link and appreciate any advise:
https://publish-p56999-e462086.adobeaemcloud.com/content/cmc/us/en/mkto-test.html

(we've tried the code on local host and it worked. However we can't make it work when we publish it to Adobe Experience Cloud)

Thank you.

[SanfordWhiteman · Accepted solution]

You can’t set cookies at the domain adobeaemcloud.com because that’s considered a public domain suffix, i.e. listed on the PSL.

Public domain suffixes are like implicit or effective TLDs. They’re technically private in the sense that they’re controlled by a private entity. But they’re shared by multiple tenants of that entity, so it wouldn’t be safe to have one tenant read another tenant’s cookies.  As a result you’re only allowed to set cookies at your specific subdomain, publish-p56999-e462086.adobeaemcloud.com. Note this is a browser restriction, not related to Marketo or Munchkin.

[VictoriaWang]

Thanks for your advise and we successfully initiated Munchkin cookie on our AEM site by adding domain level 3 parameter!Our method:
We couldn't build Munchkin Extension with Domain Level 3 in Adobe Data Collection, so we disabled Munchkin Extension and added the following script in AEM site:
<script type="text/javascript" src="//munchkin.marketo.net//munchkin-beta.js"></script>
<script>Munchkin.init('379-BFK-875', {domainLevel: 3});</script>