Stairs to the balcony and some lights

 I'd started to play today and made a video. After 10 minutes it stopped and said my world was "corrupted and couldn't be saved". All the work I had done was gone...for the day. I had saved my worlds file so I could take it back if something happened. But my video was lost. As I start in this video, you see I have already started on the stairs and made benches.