Sitecore Marketing Automation Engine failed to start - Workaround for local development

There are several blogposts related to Sitecore Marketing Automation Engine service which is not getting started and Sitecore installation abruptly stops. If it is failing in a production instance, then please do refer the blogpost links at the bottom of this blog to find the root cause and fix it. 

In case, it is for a local development instance and you just want to complete the installation and bring up the Sitecore, you can do the following workaround to install the Sitecore successfully and also bring up the Sitecore Marketing Automation Engine service. 

Installation using SIF:

Edit the xconnect-xp0.json file, go to StartServices task and remove the params to start the marketing automation service. This will allow you to complete the Sitecore installation. Basically we are removing the task to start the service as part of the installation. 

        "StartServices": {
            "Description": "Starts the service.",
            "Type": "ManageService",
            "Params": [
                {
                    "Name": "[variable('Services.IndexWorker.Name')]",
                    "Status": "Running"
                },
                {
                    "Name": "[variable('Services.ProcessingEngine.Name')]",
                    "Status": "Running"
                }
            ]
        }

Installation using sifon or SIM:

Open the compressed installation package using 7-Zip (SIF - \AppData\Roaming\Sitecore\Sitecore Instance Manager\Repository or sifon - c:\Program Files\Sifon\Downloads\), edit the xconnect-xp0.json file directly inside the package, go to StartServices task and remove the params to start the marketing automation service. This will allow you to complete the Sitecore installation.

Start Sitecore Marketing Automation Engine:

Most of the time, this issue happens due to certification. So we can let the xConnection to ignore the certificate validation. Since it is a local development environment, edit xConnect application AppSettings.config, and remove entry with key - validateCertificateThumbprint, save it. Recycle the xConnect application pool and try to start the Sitecore Marketing Automation Engine service and it should work. 

  <!-- Remove this entry and save it. -->
  <add key="validateCertificateThumbprint" value="A24A5C1386846F69A69BD8C0BCC78FA1454872E1" />  

Related blogposts to find the root cause and fix it:

http://www.nehemiahj.com/2021/06/sitecore-marketing-automation-engine.html

installation failure, fails to start marketing automation service - Installation and Upgrading Sitecore - Developers - Sitecore Community

Sitecore 9.1 Failed to start Marketing Automation Service – Sitecore Endeavor (wordpress.com)

xConnect The HTTP response was not successful: Unauthorized - Sitecore Stack Exchange