Media no longer displays // code: 406, type: "FILEREF_UPGRADE_NEEDED"

[romanrm]

Some (most?) media seems to have stopped displaying in the web version today for me. The error is:

Download image failed Object {code: 406, type: "FILEREF_UPGRADE_NEEDED", description: "CODE#406 FILEREF_UPGRADE_NEEDED", originalError: Object, handled: true}