Sean Gallardy explains access violations:
Access Violations (AV) are another common error that will cause SQL Server to take a memory dump. These can occur for a variety of reasons, and unlike the last one (Non-Yielding Scheduler) it’s quite the task, especially given public symbols don’t have structure data and offsets.
Read on to see what they are, what a dump file may include, and why they can be so difficult to debug.