Sitecore XC 9 authentication issue when connecting to CE

INFO Commerce.Connector - Acquiring mapping lock
INFO Commerce.Connector - Mapping locked
INFO Commerce.Connector - Loading the mapping entries
INFO Commerce.Connector - Attempting to connect to CE
ERROR Authentication Error Exception: System.Exception Message: The certificate thumbprint is invalid or missing from your configuration, secure communication with the Commerce Engine is not possible.
ERROR Commerce.Connector - There was an error retrieving the mappings from the Commerce Service
INFO Commerce.Connector - Loaded the mapping entries - 0 Entries, 0 Parents 0 Templates
INFO Commerce.Connector - Release mapping lock
  1. The certificate I was using was for a different domain than my site binding.
  2. After creating a new certificate you will need to update the thumbnail in ~/App_Config/Include/Y.Commerce.Engine/Sitecore.Commerce.Engine.Connect.config
  3. Additionally you should verify the thumbprint is correct in your Commerce Engine role. The config.json file holds this information in the following section:
"Certificates":{
      "Certificates":[
         {
            "Thumbprint":"E4E83859CFA46F25144E2FDE0DF3ED8C44E44D7B",
            "DefaultRoles":[
               "sitecore\\QA",
               "sitecore\\Commerce Business User"
            ]
         }
      ],
      "CertificateHeaderName":"X-CommerceEngineCert"