You may receive an email from the Marketing Cloud Connect managed package with the subject: "Salesforce Marketing Cloud Connect - Action Required to Prevent Service Interruption."
This email would be sent if the package detects an issue when trying to connect your Salesforce org with your Marketing Cloud account through the Marketing Cloud Connect API User. Triggered sends created within the Marketing Cloud Connect managed package will be retried for 30 minutes before ultimately failing, unless the API User is re-integrated. Update your API user immediately to avoid interruption.
This email is deployed to any user marked as a "Marketing Cloud Connect for AppExchange Admin" in Salesforce or if your email address is used as the Support Ticket Recipient within the Marketing Cloud Connect managed package configuration screen. This email is sent from any user in your Salesforce Org that performs an action that would then attempt to utilize the managed package API User credentials, but fails due to token issues.
To avoid interruption of service with Marketing Cloud Connect, reconnect your Marketing Cloud Connect API User immediately as mentioned in the email received. Below are the instructions provided along with a link to supporting help documentation.
In the October 2019 release, JSON Web Tokens were introduced as an improved way of authenticating that can reduce the likelihood that the API user will need to be reconnected. You can find more information using the following article: https://help.salesforce.com/s/articleView?id=000354260&type=1
This error email will like occur due to Tenant-Specific OAuth Endpoints not being enabled within this MC Connector settings for your SF Org. When you enable Tenant-Specific OAuth Endpoints, it will clear your MC Configuration and prompt you to reconfigure/reintegrate. This will include going through the Automatic Setup Wizard, reconnecting the MC API user, and then setting up the MC Connector settings how it was prior to upgrading to TSE's. It may also prompt you to verify a new Remote Site Setting. If you are prompted to do so, please verify the new remote site. We also recommend taking a screenshot of the page prior to enablement, so you know how to use the same configuration settings. The path to your MC Connector Settings page is below:
Login to your SF Org > ensure you are in Salesforce Classic > navigate to the Marketing Cloud tab > click "Configure Marketing Cloud Connector"
After reaching the MC Connector settings page, you can enable "Tenant-Specific OAuth Endpoints" by scrolling to the bottom of the page to the "Advanced" section, and clicking the small arrow to expand the section. Finally, toggle "Tenant-Specific OAuth Endpoints" on.
Once you have enabled Tenant-Specific OAuth Endpoints and re-established the Marketing Cloud API User's connection, this will enable the JSON Web Token (JWT) Authentication and should prevent this issue from re-occurring in the future.
For more information around updating to TSEs within the Marketing Cloud, please review our Updating Marketing Cloud Endpoints to Tenant Specific Endpoints: FAQ Knowledge Article.
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