This is a warning to those who watch CW network shows in the Chicago area. As of September 1, CW shows will be moving from WPWR (Comcast 184/1050) to WCIU (183/1026). If you have a Legacy (non-X1) DVR and series recordings set, you will need to delete the series and recreate them on the new channel. There is an advanced option for 'Any Channel', but that usually defaults to the lowest number, which will usually be the SD channel.
For X1, I'm not sure if it will follow the change or if you need to do the same.