I moved most of my images to an S3 source and the migration went well. However I left a couple of images lurking in the old 'filesystem' folders (and thus the associated references)
When I then deleted my old File Upload Preferences references, and then visited a Publish page, I got a PHP exception error with
It appears that when Assets still has references to old folders in the DB, and those folders are deleted, it throws an exception.
Any way around this?