In the last 48 hours 6.6.1 has crashed twice during periods of no user activity. I don't have a Ryzen (I3 3240) and I don't run VMs, just Plex Docker and a couple of other minor dockers. It seems I'm not alone and I wonder why the release hasn't been pulled and why testing wasn't better. This is a mature 'paid for' product that deserves improved support and shouln't be putting out products that fail.
I've reverted to 6.5.3 so I hope that's the end for now. It might be a good idea to flag releases that have recorded major bugs so that your customers are better informed!