Marketing Cloud Connect | Salesforce Data Event | Error Activating Journey

Issue: When attempting to activate a Journey with a Salesforce Data Event within Marketing Cloud Engagement you may encounter the following error within the UI: 

UNKNOWN_EXCEPTION; You can’t activate this flow because it always runs in the system context. Your Salesforce admin can help with that.;;AutoLaunchedFlow Activate failed.

Context: Process Builder is in the process of being formally retired.   Marketing Cloud Connect record Triggered flows validate the existence of the "View all Data" permission in order to active new Journeys utilizing these or while processing existing things.     

When this error is received in the UI, it may appear that this is a net new problem.  However, the reason that this occurs is because Process Builder only validates that the "View All Data" permission exists when it is initially set up.   It does not validate whether or not the permission exists after it is initially set up.   This may lead to the belief that a new production issue is happening however this is actually being caused by a permissions change that would have occurred at any point after Process Builder was initially active.   
 

Conversely, record-triggered flows validate that the "View All Data" permission exists every time that the relevant Salesforce objects are generally utilized.