Visible crew/equipment: The "exterior" windows in Blakes 7 are a constant source of amusement. In many cases you can see the top or bottom of the board which is supposed to be the window, with empty set behind the board. Turn the brightness of your screen up to maximum and in many cases you can see that "windows" are semi-transparent perspex with light bulbs for the stars. You can often see wiring running from bulb to bulb, looped and cable-tied together, etc., through the "windows".
Blake's 7 (1978)
1 mistake in show generally - chronological order
Starring: Jan Chappell, Michael Keating, Paul Darrow, Peter Tuddenham
Trivia: The box-like entrances to the underground lair proved problematic for the Space Rat actors. When several of them were supposed to spill out on cue, the box walls and their heavy helmets prevented them from hearing the director, who repeatedly screamed "Action!" to no avail. A lone voice from inside the box eventually shouted back, "Can't hear you!"