channels not working - XFinity

This question is about "channels not working", with XFinity-Comcast TV channels, programming, and sports. Recently (past week) I have several channels that are not working. History HD ScienceHD to name a few. The message on the screen is that this channel should be available shortly. I live in zipcode 19973. Is any one else having this issue. I have rebooted the cable box to not avail. Does anyone have any suggestions.

This topic covered channels not working, and XFinity - Comcast cable tv service.