We just ran January updates on our production servers.  After the update, I have a test workflow that I use to see if anything is broken. That workflow ran fine.  This morning, I came into work with hundreds of workflow error messages.  I keep getting the Workflow Failed to Start, Cancelled by System Account.  Also, when I attempt to publish, I get a failed to publish error.  This appears to only be affecting one Site Collection.  My test workflow is in a different site collection and that workflow still runs fine.

I haven’t seen anything that would affect one site collection and not another.  

All workflows (list and site) are failing in the one site collection.