AFAIK the viewer only shows manually saved, or sentry saved, videos- not the normal contents of the 60 minute rolling "recent" footage that isn't saved long term.
If you pull the drive out at the end of a drive and plug it into a computer do you see a recent folder with clips?
As far as the "red light comes on" which one?
There's one for dashcam- which is the only feature that actually records any video.
There's one for Sentry (which itself does NOT record video ever it only moves dashcam-recorded video, the last 10 minutes worth, to the sentry folder is sentry goes to alert or alarm mode)
The sentry light can be on even if the dashcam one is not- which will result in nothing being recorded because again dashcam, not sentry, is what does the recording.